19th International Symposium on Heavy Ion Inertial Fusion

12 Aug 2012, 08:30 → 17 Aug 2012, 18:00 US/Pacific

Crystal Ballroom (Shattuck Plaza Hotel)

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Sunday, 12 August

17:00 → 19:00 Welcome reception

Monday, 13 August

08:15 → 08:50 Welcome, Introduction, & Logistics: (AM refreshments served)

08:50 → 12:40 Program overviews, Chairs: Bill Herrmannsfeldt and Grant Logan

08:50 National Research Council Assessment of the Prospects for Inertial Fusion Energy

Ronald C. Davidson Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey, 08543 USA This paper presents an overview of the National Research Council study entitled "Interim Report—Status of the Study "An Assessment of the Prospects for Inertial Fusion Energy" (National Academies Press, Washington, D.C., June, 2012, www.nap.edu). The study, commissioned by the U.S. Department of Energy, has three main elements to its charge: (a) assess the prospects for generating power using inertial confinement fusion; (b) identify the scientific and engineering challenges, cost targets, and R&D objectives associated with developing an inertial fusion energy demonstration plant; and (c) advise the U.S. Department of Energy on the preparation of an R&D roadmap aimed at developing the conceptual design of an Inertial Fusion Energy (IFE) demonstration plant. In addition to the main NRC committee addressing these three charge elements, a target physics panel established by the NRC is carrying out an assessment of the current performance of various inertial confinement fusion target technologies, and identifying the R&D challenges to providing suitable targets on the basis of parameters established and provided by the main committee. The panel is also addressing the potential impacts of the use and development of current target concepts on proliferation. While the main committeeʼs Interim Report has a limited scope and does not fully address all of the tasks in the charge to the committee, it does provide a status report on the committeeʼs progress and a summary of the committeeʼs preliminary conclusions and recommendations based on the information it received during its first four meetings (out of a total of six meetings) and from its review of relevant reports on the subject. The Final Report of the committee assessing the prospects for inertial fusion energy is presently in the NRC review process, with the goal that this report be released in the Fall of 2012.

Speaker: Ronald Davidson (Princeton University)

09:15 Experiments towards HIF at FAIR

Boris Sharkov FAIR GmbH, Planckstr.1, 64291 Darmstadt, Germany. The next generation of heavy ion drivers - the Facility for Antiproton and Ion Research in Europe, FAIR, will provide worldwide unique accelerator and experimental facilities allowing for a large variety of unprecedented fore-front research in extreme state of matter physics and applied science. Indeed, it is the largest basic research project on the roadmap of the European Strategy Forum of Research Infrastructures (ESFRI), and it is cornerstone of the European Research Area. This presentation outlines the current status of the Facility for Antiproton and Ion Research. The scope and sequence of the construction will be described. Also the physics program of FAIR with emphasis on plasma physics issues with intense heavy ion beams will be presented as well as the results of experimental activities on heavy ion accelerator facilities in Europe, providing intense beams capable of generating extreme state of matter by isochoric energy deposition regime. Considerations are focused on new experiments by using large synchrotron rings which appear to be efficient tools for investigations into the physics of high-brightness beams generation and high energy density research. Development of new diagnostic methods for high resolution parameters measurements of dense, non-ideal plasmas is discussed. Reference: www.fair-center.eu

Speaker: Boris Sharkov (FAIR GmbH)

09:40 Japanese Program Overview on HIF and Related Research Activities

K. Horioka (1); M. Nakajima, T. Kawamura, J. Hasegawa, S. Ikeda, Y. Sakai, Y. Oguri (2); K. Kondo (3); S. Kawata, T. Kikuchi (4); T. Sasaki (5); M. Murakami, K. Takahashi (6); M. Okamura, (7); K. Takayama (1) Department of Energy Sciences, Tokyo Institute of Technology (DES-TIT), Midori-ku, Yokohama, 226-8502, Japan (2) Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology (RLNR-TIT), Meguro-ku, Tokyo 152-8550, Japan (3) Department of Energy and Environmental Sciences, Utsunomiya University (UU), Utsunomiya 321-8585, Japan (4) Department of Electrical Engineering, Nagaoka University of Technology (NUT), Niigata 940-2188, Japan (5) Institute of Laser Engineering, Osaka University (ILE Osaka), Osaka 565-0871, Japan (6) RIKEN, Brookhaven National Laboratory (BNL),Upton, NY 11973, USA (7) Accelerator Research Organization (KEK), Tsukuba 305-0801, Japan Recent research activities relevant to heavy ion fusion (HIF) in Japan are reviewed briefly. During the past two years from the last HIF conference, significant progress in HIF and high-energy-density physics research has been made by a number of research groups in universities and accelerator facilities in Japan. There are strong space charge issues in ion injectors and the final stage of the high power accelerators. Although a critical issue of HIF is to transport the beams without degrading the phase space density, longitudinal beam manipulation, which is essential for the generation of energetic beams, is inevitably accompanied by a dilution of particle distribution in the phase space. Evolutions and beam dynamics in the phase space were discussed at BNL and TIT-NUT, in ion injectors and during the final bunching stage of the high power ion accelerators. Beam-plasma interaction experiments and related theoretical studies are in progress at RLNR-TIT. In the interaction experiments, a shock-heated gas was used as a well-defined dissociated hydrogen. New schemes of beam driven fusion target have been proposed and discussed by the groups at UU and ILE. A new illumination scheme was found to improve the implosion uniformity of directly-driven fusion target. As the properties of matter under high energy density/warm dense states are critically important to evaluate the hydrodynamic response of fusion pellet, dense plasmas were characterized by pulse power devices at NUT and TIT. The KEK group upgraded their induction synchrotron using 500MeV booster ring of the 12GeV synchrotron. With this system, they are planning to accelerate all species of ions without injector. When the second phase of R&D is completed, we can expect ion beams with 1010 particles per bunch regardless of ion species.

Speaker: K. Horioka (Department of Energy Sciences, Tokyo Institute of Technology)

10:05 High Energy Density Physics at ITEP

A. Golubev (1); N. Alexeev, V. Burtsev (6); V .Fortov, V. Demidov, A. Drozdovskyi, S. Drozdovskyi, S. Dudin (3); D.H.H. Hoffmann (4); S. Kartanov (6); A.Kantsyrev, S.Kolesnikov (3); A. Kozodaev, A. Khudomjasov, T.Kulevoy, А.Кuznetsov (2); D. Laykin, A. Mikhailov (6); V. Mintsev (3); N. Markov, D. Nikolaev (4); I. Roudskoy, A. Rudnev (6); B. Sharkov, N.Shilkin (4); G. Smirnov, A. Sitnikov, L. Shestov, M. Tatsenko, D. Varentsov (5); N. Zavialov, M. Zhernokletov (6); A. Utkin (3); K. Weyrich (5). (1) Institute for Theoretical and Experimental Physics, Moscow, Russia (2) Moscow Engineering Physics Institute (State University), Moscow, Russia (3) Institute of Problems of Chemical Physics, RAS, Chernogolovka, Russia (4) Technical University Darmstadt, Germany; (5) GSI-Darmstadt, Germany; (6) Russian Federal Nuclear Center - The All-Russian Research Institute of Experimental Physics, Sarov, Russia An overview of the experimental activities on high energy density in matter in progress at ITEP is given for the period since the 18th International Symposium on HIF in Darmstadt in 2010. The recent results of diagnostics detonation studies in condensed matter and of shock-wave process including shock-induced dense non-ideal plasma of argon and xenon and shock loading of non-uniform metal surfaces by proton radiography method1,2 are emphasized. The results of development RF wobbler system for shaping of hollow heavy ion beam on the target3 are presented. Supported by State contracts of Rosatom Н.4е.45.90.11.1056, Н.4е.45.90.11.1058, H.4b.45.90.11.1047, H.4b.44.90.12.1048 and RFBR Grant 11-02-01530-а. Reference. 1. S.A. Kolesnikov, S.V. Dudin, V.V. Lavrov, D.N. Nikolaev, V.B. Mintsev, N.S. Shilkin, V.Y.Ternovoi, A.V. Utkin, V.V. Yakushev, D.S. Yuriev, V.E.Fortov, A.A. Golubev, A.V.Kantsyrev, L.M.Shestov, G.N.Smirnov, V.I.Turtikov, B.Yu.Sharkov, V.V.Burtsev, N.V. Zavialov, S.A. Kartanov, A.L. Mikhailov, A.V. Rudnev, M.V. Tatsenko, M.V. Zhernokletov. Shock-Wave and Detonation Studies at ITEP-TWAC Proton Radiography Facility. Bulletin of the American Physical Society, 2011, V.56, N.6, p. 132. 2. Babochkin K.A., Golubev A.A., Dudin S.V., Kantsyrev A.V., Kolesnikov S.A., Lavrov V.V., Mintsev V.B., Savchenko A.V., Smirnov G.N., Shestov L.M., Turtikov V.I., Utkin A.V. Investigation of detonation wave structure in emulsion high explosives. Physics of Extreme States of Matter – 2011. Ed. by Fortov V.E., Karamurzov B.S., Temrokov A.I. et al. Chernogolovka, 2011, pp. 71-73. 3. A.Golubev T.Kulevoy, A.Sitnikov, S.Minaev, B.Sharkov. The system for rotate of high energy heavy ion beam. Patent for the invention No. 2422928, 27 of June 2011

Speaker: A. Golubev (Institute for Theoretical and Experimental Physics)

10:30 Discussion

10:45 Activities in heavy ion beam driven HEDP and IFE research at IMP, Lanzhou

Y. Zhao (1), Y. Wang( 2), X. Zhang (3), Z. Xu (4), Z. Hu (2), Y. Zhang (2), R. Cheng (1), Yu. Wang(1), X. Zhou (1), Y. Lei 1), L. Yang (1), J. Yang (1), G. Xiao (1), and W. Zhan (1) Institute of Modern Physics, CAS, Lanzhou 730000 China (2) Dalian University of Technology, Dalian, 116024 China (3) Xianyang Normal University, Xianyang, 713000 China (4) Xi’an Jiaotong University, Xi’an, 710049 China Recent progresses in high energy density physics and inertial confinement fusion in China are presented; primary emphases will be given to the research activities relevant to HEDP and IFE driven by heavy ion beam at IMP (Institute of Modern Physics), Lanzhou, China. Radiography of statics objects with the fast extracted high energy carbon ion beam from CSR (the cooling storage ring) has been investigated, it is found that, after some mathematic treatments of the primary radiographs, very fine inner structures of the objects can be achieved. Experiments on the interaction of low energy heavy ion beam with plasma are being carried out at the 320kV highly charged ion platform. Stopping, charge effect and the transportation properties of low energy ion beams in gas plasma will be discussed. The progresses in simulations on heavy ion driven HED will be reviewed as well. The proposed project, HIAF (High Intensity heavy-ion Accelerator Facility), as the 12th 5 year plan of China will be introduced. Exploring of HEDP and HIF will be one of the most important goals in this project. The preliminary design for the HEDP terminals of HIAF will be discussed. Above works are supported by the “973” program (the National Program on Key Basic Research Project, No. 2010CB832902) and NSFC (the National Natural Science Foundation of China No. 11075192, 11075125).

Speaker: Y. Zhao (Institute of Modern Physics)

11:10 The University of Maryland Electron Ring Program

R.A. Kishek, B. Beaudoin, S. Bernal, M. Cornacchia, D. Feldman, R. Fiorito, I. Haber, T. Koeth, Y. Mo, P.G. O'Shea, K. Poor Rezaei, D. Sutter, and H. Zhang Institute for Research in Electronics & Applied Physics, University of Maryland, College Park, MD 20742, U.S.A. The University of Maryland Electron Ring (UMER) is a unique machine that uses scaled electron beams at nonrelativistic energies (10 keV) to inexpensively model GeV beams of heavy ions over long path lengths (kilometers of transport distance). The UMER beam parameters correspond to space charge tune depressions, at injection, adjustable in the range of 0.14-0.8. Although a ring, many of the intense beam studies on UMER are applicable to linacs. This paper reviews the UMER program, which contains experimental, computational, and theoretical components. We outline the research areas of interest, recent accomplishments, and future plans, emphasizing the relevance to heavy ion drivers. Specific topics include longitudinal induction focusing and beam manipulations; generation and propagation of space charge waves, including large-amplitude solitons; bunch end interpenetration and observation of a multi-stream instability; beam halo studies; and diagnostic development. Supported by the US Dept. of Energy, Offices of High Energy Physics and Fusion Energy Sciences, and by the US Dept. of Defense, Office of Naval Research and the Joint Technology Office.

Speaker: R. A. Kishek (Institute for Research in Electronics & Applied Physics,)

11:35 Break to pick up lunch

11:55 The NDCX-II Engineering Design

W.L. Waldron, W.J. Abraham, D. Arbelaez, W.G. Greenway, J.-Y. Jung, J.W. Kwan, M.L. Leitner, S.M. Lidia, T.M. Lipton, L.R. Reginato, M.J. Regis, P.K. Roy, M.W. Stettler, J.H. Takakuwa, J. Volmering, V.K. Vytla Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA The Neutralized Drift Compression Experiment (NDCX-II) is a unique user facility for ion-beam-driven High Energy Density Physics (HEDP) and Heavy Ion Fusion (HIF) research located at Lawrence Berkeley National Laboratory (LBNL). The construction phase was completed in March 2012 and the commissioning phase has started with tests of the injector and the first 11 cells of the accelerator. A significant amount of engineering was required to meet the performance parameters required for a wide range of HEDP experiments and simultaneously exploit the hardware available from a decommissioned accelerator. The technical challenges and design of this induction accelerator are described. This work was performed under the auspices of the U.S. Department of Energy by LBNL under Contract DE-AC02-05CH11231.

Speaker: William Waldron (LBNL)

12:40 → 13:55 Lunch and discussions

13:55 → 17:30 HIF Targets - Chairs: B. Sharkov and S. Kawata - Featured Posters: A. Ortner, A Bret, I.V. Lomonosov

13:55 Heavy Ion Targets

Roger O. Bangerter Lawrence Berkeley National Laboratory Berkeley, California, 94720, USA During the last 38 years researchers have suggested and evaluated a large number of target designs for heavy ion inertial fusion. These target designs fall into a number of general categories including: 1. Direct ignition (or fast ignition) designs originally suggested by A. W. Maschke 2. Directly driven targets with dense, high-Z outer shells 3. Indirectly driven targets 4. Targets that lie somewhere on a continuum between categories 2 and 3 5. Directly driven targets with low-density ablators (without a dense outer shell) 6. Shock ignition targets In general, the categories of targets that perform better in terms of higher target gain and/or reduced driver input energy impose more stringent requirements on accelerator design. For this reason, the optimization of a fusion power plant will involve the joint optimization of the target-accelerator system. Also, the categories of targets that perform better often rely on physics that has not been studied as thoroughly as the physics of some of the categories of targets that do not perform as well. For example, directly driven target designs usually have higher predicted gain and lower predicted driver energy requirements than indirectly driven targets. Unfortunately there is a paucity of theoretical and experimental data regarding fluid instabilities in the directly driven designs. This paper will discuss the advantages and disadvantages of the various categories of targets, particularly with respect to accelerator considerations. The paper will also discuss some of the target physics issues that must be resolved to provide a more accurate assessment of the various target-accelerator options. The paper will conclude with a discussion of the connection between ion target physics uncertainties and recent results from the National Ignition Facility.

Speaker: Roger Bangerter

14:20 A look at past heavy ion target designs

Max Tabak Lawrence Livermore National Laboratory In this talk I shall describe the distributed radiator target and its several variants—the hybrid design and the close-coupled target. This target was used in the Robust Point Design reactor scenario requiring about 6MJ of 3.5-4GeV Pb ions and yielding about 400 MJ. Several design issues shall be discussed: why a radiation driven target; why a two-sided target; why low density materials were selected;and how these designs evolved from an end-radiator design. In addition, a brief review of early work on heavy ion driven Fast Ignition will be given. Lawrence Livermore National Laboratory is operated by Lawrence Livermore National Security, LLC, for the U.S. Department of Energy, National Nuclear Security Administration under Contract DE-AC52-07NA27344. LLNL-ABS-560533

Speaker: Max Tabak (Lawrence Livermore National Laboratory)

14:45 The X-target: a high-gain and robust target design for HIF

E. Henestroza and B.G. Logan Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA A new inertial-fusion target configuration, the X-target, using one-sided axial illumination has been explored [1]. This class of target uses annular and solid-profile heavy ion beams to compress and ignite deuterium-tritium (DT) fuel that fills the interior of metal cases that have side-view cross sections in the shape of an “X”. X-targets that incorporate inside the case a propellant (plastic) and a pusher (aluminum) surrounding the DT fuel are capable of assembling higher fuel areal densities ~2 g/cm2 using two MJ-scale annular beams to implode quasi-spherically the target to peak DT densities ~100 g/cm3. A 3MJ fast-ignition solid ion beam heats the high-density fuel to thermonuclear temperatures in ~200 ps to start the burn propagation, obtaining gains of ~300. These targets have been modeled using the radiation-hydrodynamics code HYDRA [2] in two- and three- dimensions to study the properties of the implosion as well as the ignition and burn propagation phases. The main concern for the X-target is the amount of high-Z atomic mixing at the ignition zone produced by hydro-instabilities, which, if large enough, could cool the fuel during the ignition process and prevent the propagation of the fusion burn. At typical Eulerian mesh resolutions of a few microns, the aluminum-DT interface shows negligible Rayleigh–Taylor (RT) and Richtmyer–Meshkov (RM) instability growth; also, the shear flow of the DT fuel as it slides along the metal X-target walls, which drives the Rayleigh–Taylor (RT) and Kelvin Helmholtz (KH) instabilities, does not have a major effect on the burning rate. An analytic estimate of the RT instability process at the Al-DT interface shows that the aluminum spikes generated during the pusher deceleration phase would not reach the ignition zone in time to affect the burning process. Also, preliminary HYDRA calculations, using a higher resolution mesh to study the shear flow of the DT fuel along the X-target walls, indicate that metal-mixed fuel produced near the walls would not be transferred to the DT ignition zone (maximum ρR) located at the vertex of the X-target. These preliminary studies need to be extended by further hydrodynamic calculations using finer resolution, complemented with turbulent mix modeling and validated by experiments, to ascertain the stability of the X-target design. [1] E. Henestroza and B. G. Logan, Phys. Plasmas 19, 072706 (2012). [2] M. M. Marinak et al., Phys. Plasmas 8, 2275 (2001) This work was performed under the support of the U.S. Department of Energy by the Lawrence Berkeley National Laboratory under Contract No. DE-AC02-05CH11231.

Speaker: Enrique Henestroza

15:10 Wobblers and Rayleigh-Taylor Instability Mitigation in HIF Target Implosion

S. Kawata, T. Kurosaki, K. Noguchi, S. Koseki, D. Barada, Y.Y. Ma (1); A. I. Ogoyski (2); J.J. Barnard and B.G. Logan (3) (1) Utsunomiya University, 7-1-2 Yohtoh, Utsunomiya 321-8585, Japan (2) Varna Technical University, Varna 9010, Bulgaria (3) Lawrence Berkeley National Lab. and Virtual National Lab. for Heavy Ion Fusion, Berkeley, California 94720, USA In the paper a dynamic mitigation mechanism for the Rayleigh-Taylor (R-T) instability is discussed together with heavy ion beams (HIBs) wobbling motion [Phys. Plasmas 19, 024503(2012)]. In general a perturbation of physical quantity would feature the instability onset. Normally the perturbation phase is unknown so that the instability growth is discussed with the growth rate. However, if the perturbation phase is known, the instability growth can be controlled by a superposition of perturbations; the most well-know mechanism is a feedback control to compensate the displacement or the distortion of physical quantity. If the perturbation is induced by, for example, a particle beam axis oscillation or wobbling, the perturbation phase could be controlled and the instability growth is mitigated by the superposition of the growing perturbations. In actual, HIBs provide a remarkable unique tool to control the initial phases of perturbations [Phys. Rev. Lett. 104, 254801(2010)]. The wobbling HIBs can be generated in HIB accelerators and the oscillating frequency of the HIBs’ axes may be several 100MHz~ 1GHz. A direct drive spherical fuel target is illuminated by multiple HIBs and the HIBs’ axes are wobbled so that a few percent of the implosion acceleration may be oscillated in time and space. The HIB wobblers may give the controlled initial phase of each perturbation. Therefore, the HIB wobblers could realize the dynamic mitigation of the R-T instability in the fuel target implosion. In order to find the HIB wobblers’ illumination uniformity and the HIB wobblers dynamics, we performed three-dimensinal computations. A few % wobbling-beam illumination nonuniformity is realized in heavy ion inertial confinement fusion (HIF) by a spiraling beam axis motion in the paper. So far the wobbling HIB illumination was proposed to realize a uniform implosion in HIF. However, the initial imprint of the wobbling HIBs was a serious problem and introduces a large unacceptable energy deposition nonuniformity. In the wobbling HIBs illumination, the illumination nonuniformity oscillates in time and space. The oscillating-HIB energy deposition may contribute to the reduction of the HIBs’ illumination nonuniformity. Three-dimensional HIBs illumination computations presented here show that the few % wobbling HIBs illumination nonuniformity oscillates successfully with the same wobbling HIBs frequency. Supported by JSPS, MEXT, CORE, ILE/Osaka Univ. and KEK.

Speaker: S. Kawataa (Utsunomiya University)

15:35 Discussion

15:50 Tamped Heavy Ion Targets

The deeply penetrating nature of heavy ion beams makes for unique opportunities in the design of ICF targets. We describe a class of targets that take advantage the long range and Bragg peak-like deposition profile of to drive an implosion contained within a dense, high-Z tamper. The The targets consist of spherical shells of DT ice, plastic, and a thin gold tamper. The design uses two different mechanisms to provide pressure to drive the implosion. Early in time, the heavy ion beams volumetrically heat the plastic layer, whose tamped expansion compresses the fuel. As the pusher density blows down, the drive transitions to radiation driven ablation with the gold tamper now acting as a spherical hohlraum. We will discuss ongoing studies on the hydrodynamic stability of these targets and the implications for illumination uniformity.

Speaker: Matt Terry (Los Alamos National Laboratory)

16:15 Impact Ignition Design under Axi-symmetric Illumination System

M. Murakami Institute of Laser Enginering, Osaka University Suita, Osaka 565-0871, Japan In impact ignition scheme, a portion of the fuel (the impactor) is accelerated to a super-high velocity beyond 108 cm/s, compressed by spherical convergence, and collided with a precompressed main fuel. The collision generates strong shock waves in both the impactor and the main fuel. Since the density of the impactor is generally much lower than that of the main fuel, the pressure balance ensures that the shock-heated temperature of the impactor is significantly higher than that of the main fuel. By this collision, the kinetic energy of the impactor is directly converted to the thermal energy corresponding to temperatures beyond 5 keV, which is required for ignition. Thus the impactor itself becomes an igniting hot spot under isobaric configuration. The implosion symmetry is one of the crucial issues, and here we propose the optimization of polar drive illumination system for impact ignition, in which both direct and indirect schemes are considered. The beams are divided into two groups, one for the impactor and the other for the main fuel. The beams are irradiated in off-axis configuration with temporal evolution taken into account. We also present a new type of compression of fuel in the use of hyper-spherical shock compression, in which owing to the enhanced geometrical accumulation, the shock-compressed densities and pressures turn out to be substantially higher than ones achieved by spherical shocks. Detailed linear stability analysis limited to spherical geometry reveals a new dispersion relation with cut-off mode numbers as a function of specific heats ratio, over which eigenmode perturbations are smeared out in the converging phase. Supported by Japan Society for the Promotion of Science (JSPS)

Speaker: M. Murakami (Institute of Laser Enginering)

16:40 Fusion Ignition Simulations using a Particle Code

Richard M. More (1,2) (1) HIFS-VNL, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA (2) Lawrence Livermore National Laboratory, East Avenue, Livermore, CA A molecular dynamics (MD) particle simulation code has been developed to study inertial fusion ignition physics including effects of a non-Maxwellian ion velocity distribution. 10,000 DT ions at density 100 g/cm3 and temperatures of several keV are followed for 10 to 20 psec. The simulation includes ion-ion collisions, electron-ion coupling and emission and absorption of radiation. Fusion reactions produce energetic alphas; the alphas deposit energy to electrons and have Coulomb collisions with ions and the plasma self-heats to 20-30 keV. This simulation using realistic particles and interactions poses the scientific challenge of including quantum processes (fusion, radiation) in a classical particle simulation and the computational challenge of following the calculation for long enough to see significant plasma self-heating. The paper gives a detailed discussion of special physical and numerical techniques which make it possible to do such a simulation. The most important new physics in MD simulations is the possibility to describe a non-Maxwellian ion velocity distribution f(v); fusion reaction rates are very sensitive to the high-energy tail of f(v), which depends delicately on plasma transport and equilibration processes. Although equilibrium ion-pair correlation is not strong in multi-keV plasmas we find dynamical correlations caused by alpha-particle energy transfers. It is found that calculations starting from a variety of initial conditions evolve to follow a unique self-heating trajectory, an ignition attractor. Calculations starting with 3 keV DT heat to ignition within a few psec after a pulse of energetic ions are injected; this shows that fast ions are quite effective for fast ignition of pre-compressed DT. A series of such calculations help identify the threshold ion deposition heating required to ignite DT fuel within a short time of peak target compression. This work was supported in part by Department of Energy under Contract DE-AC02-05CH11231 at the Lawrence Berkeley National Laboratory and under Contract DE-AC52-07NA27344 at the Lawrence Livermore National Laboratory.

Speaker: Richard More (Lawrence Livermore National Laboratory)

17:05 Two stage focusing for FAIR and HIAF

B. G. Logan Key elements of a 44 page MathCAD study will be presented for two-stage longitudinal drift compression and final focusing of 200 GeV heavy ions using a combination of a dE/dx wedge for large (20-30%) tilt generation close to an X-target, followed by a shaped powered lithium lens for final achromatic focus. Key feasibility aspects of this concept include how wedge-shaped beam absorbers might be used to generate large velocity tilts with acceptable scattering, and how B-theta final lens might be modified to focus the velocity chirped, radially correlated drift compressed beam velocity spectrum to a common focus (self-beam generated foil stacks for X- ignition test targets, and pulse-powered lithium lens for FAIR and HIAF HEDP targets).

Speaker: B. Logan

17:30 → 19:30 Dinner (on your own)

19:30 → 22:00 X-Target Workshop (E. Henestroza, chair)

Tuesday, 14 August

08:15 → 08:30 Daily Logistics: (AM refreshments served)

Conveners: John Barnard (LBNL), Peter Seidl (LBNL)

08:30 → 12:00 Accelerator physics and technology I - Chairs: J. Kwan and A. Faltens - Featured Posters: R. Burke, K. Fukushima, T. Yoshimoto, R. Cassel

08:30 Multiple beam induction linacs

Peter Seidl (LBNL) , J.J. Barnard (LLNL), A. Faltens (LBNL), A. Friedman (LLNL), W. Sharp (LLNL), W. Waldron (LBNL) For heavy-ion driven inertial fusion energy, induction accelerators are appealing because of their higher efficiency and of the demonstrated capability to accelerate high beam current (10 kA in some applications). Accomplishments and challenges are summarized. HIF R&D has demonstrated the production of single ion beams with the required emittance, current, and energy, suitable for injection into an induction linac. Driver scale beams have been transported in quadrupole channels over short distances. None of the experiments to date have demonstrated transport and acceleration of multiple, parallel driver scale beams at the required repetition rate. Finally, we describe near-term research objectives to justify and to reduce the risks associated with heavy ion drivers based on induction accelerators. This research would be essential to justify a heavy-ion research facility capable of heating matter to fusion relevant temperatures and densities, and also to test and demonstrate an accelerator architecture that scales well to a fusion power plant.

Speaker: Peter Seidl (LBNL)

08:55 Beam Dynamics for Induction Accelerators

Edward P. Lee Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA An induction linac uses pulsed power that is applied directly, without any intervening resonant cavities, to accelerate a charged particle pulse. Relative to an rf linac this approach allows for a large beam pipe aperture capable of transporting a large current with a long pulse duration. The mean accelerating gradient is expected to be relatively low (less than about 1.5 MV/m), but the potential efficiency of energy transfer is large. A multiple-beam induction linac is therefore a natural candidate accelerator for a heavy ion fusion (HIF) driver. However, the accelerated beams must meet stringent requirements on occupied phase space volume in order to be focused accurately and with small radius onto the fusion target. Dynamical considerations in the beam injector and linac, as well as in final compression, final focus and the fusion chamber, determine the quality of the driver beams as they approach the target. Requirements and tolerances derived from beam dynamics strongly influence the linac configuration and component design. After a brief summary of dynamical considerations, two major topics are addressed here: transportable current limits, which determine the choice of focal system for the linac; and longitudinal control of the beams, which are potential destabilized by their interaction with the pulsed power system. This work was supported by the Director, Office of Science, and Office of Fusion Energy Sciences, of the U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

Speaker: Edward Lee

09:20 KEK Digital Accelerator and Latest Switching Device R&D

K. Takayama (1,2,3); K. Okamura1, T. Adachi (1,2); T. Arai, D. Arakawa (1); H. Asao (4); Y. Barata, S. Harada (5); T. Iwashita (6); E. Kadokura (1); T. Kawakubo1, T. Kubo1, Liu Xingguang (1,3); H. Nakanishi (1); Y. Okada (4); K. Okazaki (6); Y. Ohsawa (7); H. Someya (1); Leo Kwee Wah (2); M. Wake (1); and T. Yoshimoto (1,3) (1) High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan (2) Graduate University of Advanced Studies, Tsukuba, Ibaraki, Japan (3) Tokyo Institute of Technology, Nagatsuda, Kanagawa, Japan (4) NEC Network-Sensor, Futyu, Tokyo, Japan (5) Tokyo City University, Todoroki, Tokyo, Japan (6) Nippon Advanced Technology Co. Ltd. (NAT), Tokaimura, Ibaraki, Japan (7) Sun-A CORPORATION, Miyoshi, Hiroshima, Japan The digital accelerator (DA), which is a small-scale induction synchrotron [1] requiring no high-energy injector accelerator and capable of providing a wide variety of ions, has been constructed at KEK [2]. Since the last year beam commissioning has been carried out. The KEK-DA consists of a 200 kV high voltage terminal, in which a permanent magnet x-band ECRIS is embedded, 15 m long LEBT, electro-static injection kicker, and a 10 Hz rapid cycle synchrotron equipped with the induction acceleration system. An ion pulse chopped in 5 micro-sec by the newly developed Marx generator driven Einzel lens chopper was guided through the LEBT and injected by the electrostatic kicker in one turn. The 3 micro-sec ion pulse was successfully captured with a pair of barrier voltage-pulses of 2 kV and accelerated up to 12 MeV with another flat induction-acceleration voltage-pulse through a full acceleration period of 50 msec. Beam commissioning has been started with a He1+ ion beam of 100 microA. Details of fully digital-controlled barrier bucket trapping and induction acceleration are described. For continuously upgrading the induction synchrotron, we have been developing the next generation of switching power supply [3] employing noble solid-state switching elements, such as SI-Thyristor and SiC-JFET. Unfortunately packages of these elements, which can be utilized in modern accelerator performance, are not commercially available and not expected even in future. Our accelerator society must develop devices to meet their own specification, such as 1 MHz CW operation and output current/voltage of 100 A/2 kV. Recent activities on this subject at KEK will be introduced. [1] K.Takayama and R.J.Briggs (Eds), “Induction Accelerators”, (Springer, 2010). [2] T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB 14, 071301 (2011). [3] K.Okamura et al., “Characterization of SiC JFET in novel packaging for 1 MHz Operation”, Materials Science Forum 717-720, 1029-1032 (2-12).

Speaker: K. Takayama (1High Energy Accelerator Research Organization)

09:45 Discussion

10:05 Modeling HIF Relevant Longitudinal Dynamics in UMER

B. Beaudoin, S. Bernal, I. Haber, R.A. Kishek, T. Koeth and Y. Mo Institute for Research in Electronics and Applied Physics University of Maryland - College park, Maryland, 20742, USA A unique challenge for heavy ion fusion drivers is achieving sufficiently low emittances and small energy spread in the presence of intense space-charge to achieve the high deposition densities necessary for pellet ignition. The University of Maryland Electron Ring (UMER) uses intense low-energy electron beams to access the scaled physics of HIF drivers. In particular the long path length propagation in UMER presents a unique opportunity to study, at realistic scales the longitudinal beam dynamics and manipulations required for such a driver. With the use of induction modules, as in the ion machines such as NDCX-II, the resulting bunch dynamics show evidence of space-charge waves excited by an initial mismatch between the detailed initial beam distribution at the bunch ends and the applied focusing waveforms, persisting with multiple damped reflections propagating along the bunch flat-top. With sufficient amplitude, we have also been able to demonstrate steepening and the formation of solitary waves from initial modulations. With the use of sufficiently fast diagnostics we have been able to measure the dispersive transverse effects dependent on the longitudinal dynamics from both edge erosion as well as space-charge wave dynamics. This experimental work has also been very closely coupled with a simulation effort that has shown excellent agreement when the detailed longitudinal dynamics of the experiment are carefully incorporated into the model. Supported by the US Dept. of Energy, Offices of High Energy Physics and Fusion Energy Sciences, and by the US Dept. of Defense, Office of Naval Research and the Joint Technology Office.

Speaker: B. Beaudoin (Institute for Research in Electronics and Applied Physics)

10:30 Accelerator Design for FAIR and Application to HIF

Peter Spiller GSI, Darmstadt 64291, Germany New developments for the FAIR accelerator complex and the present status of operation and performance of the GSI accelerator facilities are presented and compared to the GSI HIDIF study approach. New technical solutions and developments with relevance to the RF based HIF driver scenario will be presented. Technical challenges and issues for achieving driver performance will be addressed.

Speaker: Peter-Juergen Spiller (GSI Darmstadt)

10:55 Studies of Electrical Breakdown Processes across Vacuum Gaps

L. R. Grisham, A. von Halle, A. F. Carpe, Guy Rossi, K. R. Gilton, E. D. Macbride, E. P. Gilson, A. Stepanov, T. N. Stevenson Princeton University Plasma Physics Laboratory P. O. Box 451, Princeton, New Jersey, 08543, USA The voltage which can be sustained across any given distance in a vacuum without engendering electrical breakdown forms the principle constraint upon the performance of electrostatic accelerators, determining the length, the electric field gradients, and the electrostatic lens strength which can be obtained. Despite its practical importance, the physical mechanisms governing spontaneous electrical breakdown across vacuum gaps remain somewhat obscure, consisting more of hypotheses than consistent theoretical descriptions. These fall into two main categories: electron emission and the clump hypothesis (that charged clumps detached from the electrode accelerate across the gap and vaporize the other electrode). The first of these fails to reproduce the conventionally observed scaling of voltage holding with distance for gaps larger than a cm when only the electric fields are considered, while the latter does, but seems physically improbable in its original form. We discuss our recent preliminary experiment to investigate whether electron field emission can be circumvented by using a large electric current to envelope the electrode at cathode potential with a magnetic field which is everywhere parallel to the surface planes of the electrode. This experiment did not find evidence of increased voltage holding with the magnetic field present, but it suffered from some limitations, which will also be mentioned. While this experiment was designed as a practicality test, since it used a magnetic field which would be tenable for some accelerator applications, a future test will be intended to test the physical principal of whether field emission is the governing mechanism in vacuum electrical breakdown by using an order of magnitude higher magnetic field. We describe how the second experiment can be implemented, and we also discuss possible implications of the null result from the first experiment, namely, the clump hypothesis might be closer to the correct description of the genesis of vacuum electrical breakdown than electron field emission. To this end, we discuss our suggestion that bacteria spores and husks might be the “clumps” in the clump hypothesis, and how this might be tested. It is hoped that better understanding of electrical breakdown phenomena might lead to more reliable operation of electrostatic accelerators, and perhaps also higher electric field gradients. Supported by USDOE contract no. DE-AC02-09CH11466

Speaker: L. R. Grisham (Princeton University Plasma Physics Laboratory)

11:20 The Single Pass RF Driver

Robert Burke Fusion Power Corporation Santa Cruz, CA 95060 In the closing summary of the 4th international HIF workshop in 1979, Burton Richter declared the RF driver fatally flawed because of the “black cloud” problem in storage rings. The Single Pass RF Driver (SPRFD) concept arose in part from the need to dispel that cloud. Eliminating storage rings from the driver concept does that, and much more. Designing the driver without storage rings avoids the emittance increase that accompanies multi-turn injection into storage rings. This brings into play the much lower emittance of the beams at the output from the linac. The key means to replace the beam-compaction effect of storage rings is the use of multiple isotopes, which was first proposed in 1978 and validated by the HIDIF study in the mid 1990s. Like the 1978 proposal, the Single Pass RF Driver uses ten isotopes for the Compression pulse. A major benefit of the much lower emittance at the target is the 50µm spot for Fast Ignition, as used by Basko’s pellet. The 10-fold enlargement of the phase space, with ten different particle species, could be translated to reducing the number of each kind of ion. That would be the wrong translation. SPRFD applies the design opportunities to step up the driver parameters, by quantity (e.g., 20MJ for compression) but also through improvements of implosion efficiency. The sum of all SPRFD’s advantages introduces a new paradigm for development of fusion power: Make the design as conservative as possible. The SPRFD invests the phase-space wealth of multiple isotopes in beam restructuring—from long and spindly at the front end to compact and powerful at the target. Multiple isotopes also are used to provide components of the driver pulse that treat a number of details that are important for realistic implosions. SPRFD’s sequence of beam manipulations is straightforward and uses existing technology. For Fast Ignition, using a different set of isotopes, with ranges shorter by ≥7x than the Compression isotopes, reduces peak power requirement importantly. The shortened range of these ions is ~0.9-1g/cm2, i.e., the ρ•L of the fuel mass whose ρ•R=0.5g/cm2. SPRFD’s flexibility includes, besides the time profile, using the shorter-range ions to implode the cylindrical end-caps while the longer-range ions implode the cylinder barrel. The talk will summarize features that delineate and distinguish the SPRFD concept. The talk also will describe the unique, new driver benefits for implosion performance that arise from the SPRFD’s features.

Speaker: Dr Robert Burke (Fusion Power Corporation)

12:00 → 14:00 Lunch (on your own)

14:00 → 16:30 Accelerator physics and technology II - Chairs: R. Bangerter and P-J SPiller - Featured Posters: M.A. Dorf, R. Galloway, I. Brown, S. Ikeda

14:00 Simulations of ion beams for NDCX-II

D.P. Grote, A. Friedman and W. M. Sharp Lawrence Livermore National Laboratory, Livermore CA, 94550, USA NDCX-II, the second neutralized drift compression experiment, is a moderate energy, high current accelerator that is designed to drive targets for warm dense matter and IFE-relevant energy coupling studies and to serve as a testbed for high current accelerator physics. Much of the design and characterization of the accelerator has depended on simulation. Various areas will be discussed. An overview of past work will be given, focussing on ensembles of simulations carried out to understand the effect of machine errors on the performance of the beam on the target. Thorough modelling ofthe performance requires a fully kinetic simulation of the beam and plasmainteractions. Such simulations will be discussed, showing the presence of theelectron-ion two stream instability, and illustrating some ramifications on the beam performance. The initial operation of NDCX-II was done with both single solenoid and five solenoid scenarios. Simulations that were used to help understand the results will be shown, including the effect of source-limited emission. A fit to emission data from a source test stand was developed and used inthese simulations. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Speaker: D. P. Grote (Lawrence Livermore National Laboratory)

14:25 Simulations of beams in plasmas

Pending abstract from Vay (LBNL)

Speaker: Jean-Luc Vay

14:50 Beam dynamics in a 1D beam model

Abstract pending from Steven Lund, LLNL

Speaker: Steven Lund

15:15 Discussion

15:40 Electron clouds in HIF drivers

Pending from Ronald Cohen, LLNL

Speaker: Ronald Cohen (LLNL)

16:05 Radio-Frequency and Magnetic Trap Simulations of Beam Propagation over Long Paths

H. Okamoto, M. Endo, K. Fukushima, H. Higaki, K. Ito, K. Moriya, and S. Yamagichi Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan An overview is given of the novel beam-dynamics experiments based on tabletop non-neutral plasma traps at Hiroshima University. We have designed and constructed two different types of trap systems, one of which uses a radio-frequency electric field (Paul trap) and the other uses an axial magnetic field (Penning-Malmberg trap) for transverse plasma confinement. These systems are called “S-POD (Simulator for Particle Orbit Dynamics)”. S-POD can approximately reproduce the collective motion of a charged-particle beam propagating through long alternating-gradient (AG) focusing channels, thus enabling us to study various beam-dynamics issues without relying on large-scale accelerators. So far the linear Paul traps have been applied for the study of resonance-related issues including coherent stop-band excitation and its dependence on AG lattice structures, resonance crossing in fixed-field AG accelerators, ultralow-emittance beam stability, etc. We have often made use of 40Ar+ plasmas for Paul trap simulations while 40Ca+ ions coolable with compact semi-conductor lasers are occasionally chosen for ultracold beam experiments. The dimension of the traps is smaller than about 20 cm and the operating frequency of the current systems is in the range of 1 – 2 MHz. The typical lifetime of an ion plasma, even without pre-conditioning by buffer-gas or Doppler cooling, exceeds a few seconds corresponding to millions of FODO cells. On the other hand, the Penning-Malmberg trap with multi-ring electrodes has been applied mostly for the study of beam halo formation driven by initial disturbance. For this purpose, only pure electron plasmas have been employed, but we are now planning to confine heavy ions as well by increasing the magnetic field strength. In this paper, we briefly explain how S-POD works and then summarize recent experimental results on resonance effects and halo formation. Supported in part by a Grant-in-Aid for Scientific Research, Japan Society of the Promotion of Science.

Speaker: H. Okamoto (Graduate School of Advanced Sciences of Matter)

16:30 → 16:55 Target fabrication

16:30 A Brief History of Target Fabrication at GA – Will We Have Targets To Allow Economically Feasible Inertial Fusion Energy?

D.T. Goodin, N.B. Alexander, B.E. Blue, J.T. Bousquet, L.C. Carlson, M.P. Farrell, D.T. Frey, J.F. Hund, A. Nikroo, R.W. Petzoldt, R.W. Stemke, and R.B. Stephens General Atomics 3550 General Atomics Court, San Diego, CA, 92121 USA Target fabrication for inertial fusion applications requires development and implementation of novel processes using state-of-the-art equipment. Materials science, precision engineering and machining, and nano-scale optical and x-ray characterization are utilized. Work on targets for inertial fusion began decades ago. Current-day physics and high energy density experiments have led to sophisticated target fabrication and characterization methods. General Atomics became involved with target fabrication in the early 1990’s, as the Department of Energy’s inertial fusion target support contractor. Since that time, GA has contributed to IFE programs for direct drive, indirect drive, and Z-pinch based fusion energy. Significant work was done for Inertial Fusion Energy (IFE) target mass production on the High Average Power Laser (HAPL) program for laser-based IFE as well as for Heavy Ion Fusion (HIF). The economic mass production of targets is one of the requirements for IFE, since typical power plant design studies indicate the target consumption rate is typically on the order of 500,000 per day. This review paper will follow the history of various target designs including the ICF and IFE programs, showing why we believe economical mass-production for power plants is feasible. Recent target concepts for HIF will be noted (the “X-target”) – along with potential fabrication pathways for these target designs. This review supported by General Atomics funding.

Speaker: Daniel Goodin (General Atomics)

17:00 → 19:30 Dinner (on your own)

19:30 → 22:00 High Energy Density Laboratory Physics Workshop (P. Ni, chair)

Wednesday, 15 August

08:15 → 09:30 Ion sources - Chair: K. Horikoa - Featured Posters: W.M. Sharp, M. Koepke, Y. Oguri, A. Yuen

08:15 Ion Sources for Heavy Ion Fusion

Joe W. Kwan Lawrence Berkeley National Laboratory Berkeley, CA, 94720, USA Heavy Ion Fusion requires ion beam, with several MJ energy, to compress and heat a fusion target to the required density and ignition temperature. Typical beam pulse length at the target is ~10 ns with beam current at ~ 100 kA (total charge ~ 1 mC) and energy at several GeVs. Even shorter pulse length is required for fast ignition beams. Beam pulse compression is needed because the beam pulse length at the ion source can be as long as 10 to 100 μs. Furthermore, even with a very high current density at the ion source, limitations from the injector and the accelerator beam transport physics will demand an accelerator system that is composed of multiple beams. Depending on the requirement of the final beam kinetic energy, as dictated by the HIF target design, the total beam current can vary. For example, a 60 GeV ion driver system will require 10 times less beam current (or charge) than a 6 GeV system. Most likely, an RF accelerator system will be used to produce 60 GeV beams, whereas an induction system will be used to produce 6 GeV beams with high current. The transverse emittance is an important factor limiting the ability to focus the beam current onto a small target spot. In other words, the HIF ion source must be simultaneously high current and high brightness. Often time, these two requirements are in conflict, e.g., the emittance increases with beam diameter at the ion source. Likewise, transverse merging of an array of small beamlets will cause emittance growth. Heavy ions of ~200 amu are best suited to meet the stopping-power (dE/dx) requirements. Furthermore, it is desirable to use high charge state heavy ions in order to minimize the accelerator beam voltage (i.e. the accelerator length). Unfortunately, it is difficult to make high current beams with ions of a single (pure) high charge state. Improvement in this area can result in significant cost saving in fusion driver development. In this paper, we review the scaling laws that govern the injector design and the various ion source options including the contact ionizers, the aluminosilicate sources, the plasma sources, the ECR sources, and the metal vapor sources. Supported by USDOE OFES under contract no. DE-AC02-05CH11231

Speaker: Joe Kwan

08:40 Laser Ablation Ion Source

M. Okamura (1,3); K. Kondo (1,2); K. Takahashi (2) (1) Brookhaven National Laboratory, Upton, NY, USA (2) Tokyo Institute of Technology, Tokyo, Japan (3) RIKEN, Saitama, Japan In Brookhaven National Laboratory (BNL), several laser ion source (LIS) development projects are in progress. By combining accumulated technologies, a feasible scenario of a LIS for heavy ion fusion is discussed. As a part of NASA space radiation laboratory (NSRL) program, a low charge state laser ion source (LIS) is being built to provide various species. A laser power density on the source target materials is carefully adjusted to provide the required beam specifications. The target current and ion beam pulse length are several hundreds micro ampere and several hundreds micro seconds. Stable 5 Hz ion beam generations have been demonstrated with good beam emittances. Currently, laser ablation plasma confinement technique by a solenoid magnetic field is being studied intensively. The laser system has twin Nd-YAG 850 mJ Q-switched oscillators. The wavelength and pulse width (laser) are1064 nm and 6 ns (FWHM). It has been proved that a LIS can provide low emittance low charge state beams from heavy materials including bismuth and gold. Simultaneously, we are developing a high current heavy ion RFQ using direct plasma injection scheme (DPIS). In the DPIS, a laser ablation plasma created by a LIS is transported directly to an RFQ’s entrance with neutral plasma state. By avoiding an ion extraction at the source, a severe beam loss in the low energy transport line can be eliminated. The measured currents after our RFQ showed more than 70 mA of aluminum and iron beams. These results indicate a few hundreds mA heavy ion beam acceleration with DPIS is feasible. In 2011, we started a new program which is to develop high current high charge state heavy ion LIS dedicated to a digital accelerator of KEK. A newly designed ion source chamber is being fabricated in KEK and will be delivered to BNL. For this program, we use a sub-nano second 500 mJ Nd-YAG laser system. A sub-nano second laser system enables to obtain 10E14 W/cm2 of laser power density on the target and may provide highly charged heavy ions. This shorter pulse width laser also may suit to a HIF LIS. We plan to examine low charge state ion beam production using the new laser system. The program is partially funded by RIKEN. Using the new technologies developed in the above programs, we propose a LIS to realize the HIF. Supported by USDOE, JSPS and RIKEN

Speaker: Masahiro Okamura (BNL)

09:05 Lithium Ion Sources

Prabir K. Roy, Wayne Greenway, Dave P. Grote, Joe W. Kwan, Steven M. Lidia, Peter A. Seidl, and William L. Waldron Lawrence Berkeley National Laboratory (LBNL), One Cyclotron Road, Berkeley, CA 94720, USA A lithium ion beam is attractive as it requires lower energies than other widely uses ions, such as K+, Cs+, Na+, to transport up to the targets for warm dense matter studies. Recently, a 10.9 cm diameter lithium ion source has been chosen as a source of ≈100 mA lithium ions for Neutralized Drift Compression Experiment (NDCX-II) at LBNL. In general, the common usage of lithium ion beams in magnetically confined fusion experiments for plasma diagnostics. R & D was carried out prior to NDCX II source design. A space-charge-limited emission with current densities exceeding 1 mA/cm2 was measured from 0.64 cm diameter lithium alumino-silicate ion sources when operating at ∼12750C. The lifetime of a thin coated (on a tungsten substrate) lithium alumino-silicate source was varied within 40 to 100 hours when pulsed at 0.05 Hz and with pulse length of ∼6 μs each, i.e., a duty factor of 3×10-7, at an operating temperature of 1250 to 12750C. This lifetime variation could be due to the variation of amount of lithium alumino-silicate mass deposition on the substrate surface. This article describes preparation of lithium β-eucryptite compound, typical current density and the lifetime. NDCX-II 10.9 cm diameter source performance will also be addressed as we progress in commissioning the NDCX-II machine. Work performed under auspices of U.S. DoE by LLNL, LBNL, & PPPL under Contracts DE-AC52-07NA27344, DE-AC02-05CH1123, & DEFG0295ER40919.

Speaker: Prabir Roy

09:30 → 09:45 Daily Logistics

Conveners: John Barnard (LBNL), Peter Seidl (LBNL)

09:45 → 11:15 NDCX-II - Chair: G. Deutsch - Featured Posters: W.M. Sharp, M. Koepke, Y. Oguri, A. Yuen

09:45 Discussion

10:00 NDCX-II Beam Dynamics

A. Friedman, J. J. Barnard, R. H. Cohen, M. Dorf, D. P. Grote, S. M. Lund, W. M. Sharp LLNL, Livermore CA 94550 USA A. Faltens, E. Henestroza, J. W. Kwan, E. P. Lee, B. G. Logan, P. K. Roy, P. A. Seidl, J.-L. Vay , W. L. Waldron LBNL, Berkeley CA 94720 USA R. C. Davidson, E. P. Gilson, I. D. Kaganovich, E. A. Startsev PPPL, Princeton NJ 08543 USA (Heavy Ion Fusion Science Virtual National Laboratory Collaboration) The Neutralized Drift Compression Experiment-II (NDCX-II) will produce ion beams for studies of Warm Dense Matter, target physics, and intense-beam dynamics relevant to heavy-ion-driven Inertial Fusion Energy. NDCX-II will accelerate a 20-50 nC Li pulse to 1.2-3 MeV, compress it to sub-ns duration in a neutralizing plasma, and focus it onto a target. We present: the NDCX-II machine layout and “physics design” [A. Friedman, et al., Phys. Plasmas 17, 056704 (2010)], including the use of high-occupancy pulsed-solenoid focusing and modified induction cells from LLNL’s Advanced Test Accelerator; unusual aspects of the beam dynamics (such as the use of the beam’s space charge to remove the applied head-to-tail energy tilt and halt the initial non-neutral compression in the accelerator); the simulation studies that enabled the design; estimates of robustness; prospects for using dipoles to correct for residual misalignments of the magnetic axis (and thereby suppress detrimental “corkscrew” oscillations of the beam centroid); plans for commissioning over the coming months; and some possible experiments using the machine itself and extensions. Work performed under auspices of U.S. DoE by LLNL, LBNL, & PPPL under Contracts DE-AC52-07NA27344, DE-AC02-05CH1123, & DEFG0295ER40919.

Speaker: Alex Friedman (LBNL)

10:25 NDCX-II Experimental Plans and Target Simulations

J. J. Barnard (1), R. M. More (1,2), P. A. Ni (2), M. Terry (1), A. Friedman (1), E. Henestroza (2), I. Kaganovich (3), A. Koniges (2), J. Kwan (2), A. Ng (4), W. Liu (2), B.G. Logan (2), E. Startsev (3), A. Yuen (2)   (1) Lawrence Livermore National Laboratory, Livermore CA, USA (2) Lawrence Berkeley National Laboratory, Berkeley, CA, USA (3) Princeton Plasma Physics Laboratory, Princeton, NJ, USA (4) University of British Columbia, BC, Canada   ​The NDCX-II ion induction accelerator construction project at LBNL was completed in March 2012, and the machine is currently undergoing commissioning, which is planned for completion by June 2013. The purpose of NDCX-II is to explore ion-driven High Energy Density Physics (HEDP) relevant to Inertial Fusion Energy. Using ions as drivers to create HEDP conditions has several features, including spatially uniform and volumetric energy deposition over diagnosable large material volumes (~1 mm in radius by a few to tens of microns in depth) for any material or surface; precise control over energy deposition with an intrinsic energy spread of a few per cent; a small shot-to-shot variation in energy and intensity; the ability to do energy accounting by measuring the transmitted beam; a benign environment for diagnostics (low debris and radiation background); high shot rates (~60 per hour); energy deposition that leaves the target in local thermodynamic equilibrium; and small beam induced magnetic fields. The initial configuration has an ion energy of 1.2 MeV, but a second stage is envisioned that would take the energy to 3 MeV. The beam is predicted to heat metal foils several microns thick in a timescale comparable to the hydrodynamic expansion timescale of the target for experiments that infer material properties from measurements of the rarefaction wave. Experiments using metallic foam targets several tens of microns thick that create shock waves will enable the inference of ion energy coupling into kinetic energy of fluid flow. Geometries with a tamping layer may be used to study the convergence of a tamper shock with the end-of-range shock, a process that can occur in tamped direct drive targets. We have carried out detailed hydrodynamic simulations of targets for several configurations, exploring how optical intensity measurements (from infrared to ultraviolet), laser doppler measurements (VISAR), and X-ray density measurements can be used to distinguish equations of state, and measure beam energy coupling in ion driven shock experiments.   *Work performed under the auspices of the U.S. Department of Energy under contract DE-AC52-07NA27344 at LLNL, and University of California contract DE-AC02-05CH11231 at LBNL and by PPPL under Contract DE-AC02-76CH03073.

Speaker: John Barnard (LBNL)

10:50 NDCX-II Commissioning Highlights

S. Lidia, W. Greenway, T. Katayanagi, J. Kwan, P. Ni, M. Regis, C. Rogers, P. Roy, P. Seidl, M. Stettler, W. Waldron E.O. Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA A. Friedman, D. Grote, W. Sharp Lawrence Livermore National Laboratory, Livermore, CA 94550 USA E. Gilson Princeton Plasma Physics Laboratory Princeton, NJ 08453-0451 USA The Neutralized Drift Compression Experiment-II (NDCX-II) is a new facility that will generate ion beam pulses for experimental studies of Warm Dense Matter and heavy-ion-driven Inertial Fusion Energy, as well as intense beam dynamics and beam-plasma interactions. The machine will generate and accelerate 20-50 nC of Li+, starting from a 10.9 cm diameter ion source. Tailored voltage waveforms from induction accelerating cells manipulate and longitudinally compress the beam current pulse duration from ~500 ns at the source to sub-ns at the target plane, while accelerating the ions from ~100 keV to 1.2 MeV. At the end of the accelerator the ions are focused to a sub-mm spot size onto a thin foil (planar) target, assisted by a space-charge neutralizing volumetric plasma and ~8 Tesla final focus magnet. Commissioning activities of the injector and downstream beamline have begun. We first describe the injector, accelerator, transport, final focus and diagnostic facilities. We then report on the results of early commissioning studies that characterize beam quality and beam transport, acceleration waveform shaping and beam current evolution. Corkscrew mode growth measurements based on capacitive beam position monitors and gated beam profile measurements are discussed. ASP and WARP simulation results are presented to benchmark against the experimental measurements. This work was performed under the auspices of the U.S Department of Energy by LLNL under contract DE AC52 07NA27344, and by LBNL under contract. DE-AC02-05CH11231.

Speaker: Steven Lidia

11:15 → 11:30 Walk to Building 58 High Bay for NDCX-II Tour

11:30 → 12:10 NDCX-II Tour

12:10 → 12:20 Arrive at Guest House for departure to LLNL and NIF Tour

12:20 → 13:30 Lunch

13:30 → 16:30 National Ignition Facility Presentation and Tour, LLNL

13:30 Badging at LLNL

14:15 Status of NIF (Lindl)

15:30 Tour of the National Ignition Facility

17:00 → 18:30 Social Event (optional)

Thursday, 16 August

08:15 → 08:30 Daily Logistics

Conveners: John Barnard (LBNL), Peter Seidl (LBNL)

08:30 → 11:40 Drift compression and final focus - Chairs: A. Golubev and R.A. Kishek - Featured Posters: A. Friedman, A. Burke, C. Helsley, Y. Sakai

08:30 Drift compression and Final Focus (review)

Igor D. Kaganovich, Edward A. Startsev, and Ronald C. Davidson Plasma Physics Laboratory, Princeton University, Princeton, New Jersey, 08543 USA Jean-Luc Vay, Steven M. Lidia, and Peter Seidl Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 Mikhail A. Dorf and Alex Friedman Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 Neutralized drift compression offers an effective means for particle beam pulse compression and current amplification. In neutralized drift compression, a linear longitudinal velocity tilt (head-to-tail gradient) is applied to the non-relativistic beam pulse, so that the beam pulse compresses as it drifts in the focusing section. The ion beam pulse current can be increased by a factor of 100 [1]. We have performed a detailed study of how the longitudinal compression of a typical NDCX-I ion beam pulse is affected by the initial errors in the acquired velocity modulation [2]. Although small parts of the beam pulse can achieve high local values of compression ratio, the acquired velocity errors cause these parts to compress at different times, limiting the overall compression of the ion beam pulse. For ballistic beam propagation, beam space charge can be well neutralized by a background plasma, if the plasma density greatly exceeds the beam density [3]. However, in this case the beam is subject to the two-stream instability that can lead to increase in the focal spot size [4]. Alternatively, good neutralization can also be achieved by a tenuous large-volume plasma. In this scheme, electrons are commoving with the beam and are not subject to the two-stream instability. Another advantage of this focusing scheme is that enhanced collective focusing can be provided by a weak applied solenoidal magnetic field [5]. The final focus design for NDCX-II should accommodate the applied beam velocity tilt. Location and strengths of several focusing solenoids should be optimized for tight focusing. Alternatively, an achromatic focusing system can be designed for simultaneous longitudinal and transverse focusing. * Research supported by the U. S. Department of Energy. References: [1] S.M. Lidia, et al, Proceedings of the 2009 Particle Accelerator Conference, Vancouver, BC, Canada, TU6PFP092; D.R. Welch, et al., Phys. Rev. ST –Accel. Beams 11, 064701 (2008); A.B. Sefkow, et al., Phys. Plasmas 16 056701 (2009). [2] I.D. Kaganovich, et al., Nucl. Instrum. Methods Phys. Res. A 678, 48 (2012); S. Massidda et al., ibid 39. [3] I. D. Kaganovich, et al, Phys. Plasmas 17, 056703 (2010). [4] E. Startsev, et al, "Effects of Beam-Plasma Instabilities on Neutralized Propagation of Intense Ion Beams in Background Plasmas ", these proceedings. [5] M. Dorf, et al, Phys. Plasmas 19, 056704 (2012).

Speaker: Igor Kaganovich (Princeton Plasma Physics Laboratory)

08:55 Chamber Transport for Heavy Ion Fusion

Craig L. Olson (1) 7628-4 Rio Grande Blvd. NW, Los Ranchos, NM 87107 Since the First Workshop on Heavy Ion Fusion (HIF) was held in Berkeley in 1976, the concept of HIF for energy production has continuously been an outstanding contender for Inertial Fusion Energy (IFE). One of the attractive features of HIF is that there exists a wide variety of heavy ion beam transport modes for beam propagation in the reactor chamber. Of course, the HIF target parameters dictate the required beam parameters, which in turn dictates which chamber transport modes are permissible. Here, we review the evolution of the required beam parameters, the evolution of the preferred chamber transport modes, and finally, how recent research on neutralized ballistic drift compression for Warm Dense Matter investigations contributes to the long-term goal of HIF. Possible heavy ion beam transport modes include hard-vacuum ballistic propagation, charge-neutralized ballistic propagation, co-moving electron neutralized ballistic propagation, charge- and current- neutralized ballistic propagation, pre-formed channel propagation, and self-pinched propagation. Possible reactor beam transport environments include dry-wall, wetted-wall, and thick-liquid wall reactor scenarios. With insights from all of the major IFE reactor scenarios (HIF, LIF, HAPL, Z-IFE, LIFE), we trace the development of the preferred HIF transport modes through several HIF studies [HIBALL-I (1981), HIBALL-II (1984), HYLIFE-I (1985), HYLIFE-II (1991), PROMETHEUS-H (1992), OSIRIS (1992), Heavy Ion LMF (1993), etc.]. For each of the possible HIF beam transport modes, we comment on possible focusing limits caused by, e.g., instabilities (two-stream, filamentation, etc.); micro-charge non-neutralization; voltage accuracy requirements for axial bunching; and emittance requirements for focusing and bunching. For the last many years, transport of heavy ion beams (with beam parameters reduced from those needed for IFE) has been investigated for applications to Warm Dense Matter. A brief summary of current research on neutralized drift compression (theory and simulations, NDCX-I, NDCX-II, possible final-focus discharge channel, etc.) is given. The importance of this research for scaling to the long-term goal of HIF for IFE is noted. (1) Sandia National Laboratories (1970-2007).

Speaker: Craig Olson (Sandia Nat. Lab. (Retired))

09:20 Plasma Sources for Drivers and NDCX-II

E. P. Gilson, R. C. Davidson, P. C. Efthimion, I. D. Kaganovich Princeton Plasma Physics Laboratory Princeton University, P.O. Box 451, Princeton, New Jersey, 08543 USA J. W. Kwan, S. M. Lidia, B.G. Logan, P. A. Ni, P. K. Roy, P. A. Seidl, W. L. Waldron Lawrence Berkeley National Laboratory One Cyclotron Road, Berkeley, California, 94720 USA J. J. Barnard, A. Friedman Lawrence Livermore National Laboratory P.O. Box 808, Livermore, California, 94550 USA A barium titanate ferroelectric cylindrical plasma source has been developed, tested and delivered for the Neutralized Drift Compression Experiment NDCX-II at Lawrence Berkeley National Laboratory (LBNL). The plasma source design is based on the successful design of the NDCX-I plasma source [1]. A 7 kV pulse applied across the 0.150″-thick ceramic cylinder wall produces a large polarization surface charge density that leads to breakdown and plasma formation. The plasma that fills the NDCX-II drift section upstream of the final-focusing solenoid has a plasma number density above 1010 cm-3 and an electron temperature of several eV. The operating principle of the ferroelectric plasma source will be reviewed and a detailed description of the installation plans will be given. The criteria for plasma sources with larger number density will be given and candidate plasma sources such as flashboards and laser ablation sources will be discussed. Ideas will be presented for plasma sources for driver applications. Plasma sources for drivers will need to be highly reliable, create plasmas reproducibly, and operate at several Hz for millions of shots. This research was supported by the U.S. Department of Energy. [1] Plasma Source Development for the NDCX-I and NDCX-II Neutralized Drift Compression Experiments, E. P. Gilson, R. C. Davidson, P. C. Efthimion, J. Z. Gleizer, I. D. Kaganovich, Ya. E. Krasik, Laser and Particle Beams, in press (2012).

Speaker: Dr Erik Gilson (PPPL)

09:45 Discussion

10:00 Study on Beam Dynamics during Longitudinal Bunch Compression using Compact Simulator Supported by Theoretical and Numerical Approaches for Heavy Ion Fusion

Takashi Kikuchi (1); Kazuhiko Horioka (2); Toru Sasaki and Nob. Harada (1) (1) Nagaoka University of Technology Kamitomioka 1603-1, Nagaoka, Niigata, 940-2188, Japan (2) Tokyo Institute of Technology, Nagatsuta 4259, Yokohama, Kanagawa, 226-8502, Japan In final beam bunch compression for heavy ion-beam driven inertial confinement fusion (ICF), i.e., heavy ion fusion (HIF), the beam dynamics with theoretical and numerical simulation approaches to investigate the limitation of longitudinal pulse compression is studied in comparison with experimental results. Transport of space-charge-dominated beams with low emittance is crucial issue for application to HIF [1-2]. However, the beam dynamics is unclear, because the beam parameters are extraordinary in comparison with the particle beams produced from conventional accelerators. It is important to clear the dynamics for the precise control of high-current beams due to effective fuel pellet implosion. Although, the beam parameters depend on the stage and the accelerator complex for HIF, high current (1 kA~100 kA) heavy ion beams are required in the final stage of the particle accelerator system. A compact simulator with an electron beam was constructed to understand the beam dynamics during the final pulse compression for ICF driven by heavy ion beams [3-5]. Not only from the view point of the experimental apparatus, but also from the view point of the numerical and theoretical approaches, the simplified and scaled simulator is useful to clear the mechanisms of beam dynamics such as the emittance growth. Using the longitudinal envelope equation, the ratio between the repulsion forces due to the space charge and the emittance was estimated [6]. The numerical simulations were carried out in the parameters of compact electron beam experimental device [6]. These theoretical and numerical approaches suggested that if the initial temperature is low enough, the compact simulator will be able to simulate the beam dynamics around the stagnation point at the unneutralized bunch compression. Additional results will be presented in this conference. [1] K. Horioka, et al., Nucl. Instrum. Methods Phys. Res. A606, 1 (2009). [2] A. Friedman, et al., Nucl. Instrum. Methods Phys. Res. A606, 6 (2009). [3] K. Horioka, et al., 18th Int. Sym. Heavy Ion Inertial Fusion (HIF2010), Darmstadt, August-September 2010, TUS-0404, Annual Report Contributions of the High Energy Density Physics Community, GSI-2011-2, p.84. [4] A. Nakayama, et. al., "Longitudinal bunch compression study with induction voltage modulator", 7th Conf. Inertial Fusion Sci. Appl. (IFSA2011), 2011, P.We_105. [5] Y. Sakai, et. al., "Study on the Dynamics during Longitudinal Compression of Intense Charged Particle Beams with Compact Simulator", in this conference. [6] T. Kikuchi, et. al., "Beam dynamics analysis in pulse compression using electron beam compact simulator for Heavy Ion Fusion", 7th Conf. Inertial Fusion Sci. Appl. (IFSA2011), 2011, P.We_104.

Speaker: Takashi Kikuchi (Nagaoka University of Technology)

10:25 Effects of Beam-Plasma Instabilities on Neutralized Propagation of Intense Ion Beams in Background Plasma*

E. A. Startsev, I. D. Kaganovich, E. Tokluoglu, R. C. Davidson Princeton Plasma Physics Laboratory, Princeton University P. O. Box 451, Princeton, New Jersey, 08543 USA In ion-beam-driven high energy density physics and heavy ion fusion applications, the intense ion beam pulse propagates through a background plasma before it is focused onto the target [1]. The streaming of the ion beam relative to the background plasma can cause the development of fast electrostatic collective instabilities [2]. These instabilities produces fluctuating electrostatic fields that cause a significant drag on the background plasma electrons and can accelerate electrons up to the average ion beam velocity. Consequently, the dominant electron current can reverse the beam self-magnetic field. As a result, the magnetic self-field force reverses sign and leads to a transverse defocusing of the beam instead of a pinching effect in the absence of instability [3]. In addition, the ponderomotive force of the unstable wave pushes background electrons transversely away from the unstable region inside the beam, which creates an ambipolar electric field, which also leads to ion beam transverse defocusing. Because the instability is resonant it is strongly affected and thus can be effectively mitigated and controlled by the longitudinal focusing of the ion beam [4]. In this paper the conditions for the formation of nonlinearly generated de-focusing self-electric and self-magnetic fields are studied in detail using the particle-in-cell code LSP [5]. The scalings of the average de-focusing forces on the beam ions due to these effects are identified and compared with proposed theoretical model. These scalings can be used in the development of realistic ion beam compression scenarios in present and next-generation ion-beam-driven high energy density physics and heavy ion fusion experiments. * Research supported by the U.S. Department of Energy. [1] A. Friedman et. all., Physics of Plasmas 17, 056704 (2010). [2] R. C. Davidson, M. Dorf, I. Kaganovich, H. Qin, E.A. Startsev, S. M. Lund, Nuclear Instruments and Methods in Physics Research A606, 11 (2009). [3] R. N. Sudan, Physical Review Letters 37, 1613 (1976). [4] E. A. Startsev, R. C. Davidson and M. Dorf, Nuclear Instruments and Methods in Physics Research A 606, 42 (2009). [5] D. R. Welch, D. V. Rose, B. V. Oliver, R. E. Clark, Nuclear Instruments and Methods in Physics Research A464, 134 (2001).

Speaker: E. A. Startsev (Princeton Plasma Physics Laboratory)

10:50 Design considerations for a wobbler in a HIF driver

Hong Qin, Ronald C. Davidson Princeton Plasma Physics Laboratory, Princeton University P. O. Box 451, Princeton, New Jersey, 08543 USA B. Grant Logan, Lawrence Berkeley National Laboratory, Berkeley, California, 94720 USA Beam wobbler systems have been recently proposed for heavy ion fusion system to achieve uniform deposition of the beam energy onto the target [1-6]. The currently envisioned wobbler systems consist of sets RF voltage driven plates on the beam path, which can be used to actively control the centroid dynamics of the beam. By choosing appropriate RF voltage wave-forms, different slices of the beam can be delivered to different locations on the target. The benefits of using such a beam wobbler system are two-fold. First, uniform energy deposition reduces the amplitude of the initial seeding for the Rayleigh-Taylor (RT) instability such that it takes longer for the RT instability to reach a larger amplitude Secondly, the time-modulation of the energy deposition due to the wobbler system also generates a significant dynamic stabilization effect for the RT instability [3,5,7]. These two effects are combined to make the beam wobbler system a useful tool for suppressing the RT instability for heavy ion fusion systems. This paper describes recent theoretical and numerical investigations of the dynamics stabilization of the RT instability with a time-dependent drive. It turns out the essential dynamics can be described by an extended Courant-Snyder theory. It is found that the reduction of growth rate has a complicated dependence on the modulation waveform. But in general, slower modulation has a larger stabilization effect. Research supported by the U.S. Department of Energy. [1] H. Qin, R. C. Davidson, and B. G. Logan, Laser and Particle Beams 29, 365 (2011). [2] H. Qin, R. C. Davidson, and B. Grant Logan, Phys. Rev. Lett. 104, 254801 (2010). [3] S. Kawata, T. Kodera, Y. Hisatomi, et al, Journal of Physics: Conference Series 244, 022003 (2010). [4] S. Kawata, K. Horioka, M. Murakami, et al, Nucl. Instr. and Meth. A 577, 21(2007). [5] S. Kawata, T. Sato, T. Teramoto, E. Bandoh, et al., Laser Part. Beams 11, 757 (1993). [6] A. R. Piriz, N. A. Tahir, D.H.H. Hoffmann, and M. Temporal, Phys. Rev. E 67, 017501 (2003). [7] R. Betti and R. L. McCrory, Phys. Rev. Lett. 71, 3131 (1993).

Speaker: Hong Qin (Princeton Plasma Physics Laboratory)

11:15 Rare Isotope Accelerator Project in Korea and Its Application to High Energy Density Sciences

M. Chung1,2, Y. S. Chung3, S. K. Kim3, and D. H. H. Hoffmann4 1Fermi National Accelerator Laboratory, Batavia, IL 60510, USA 2Handong Global University, Pohang 791-708, Korea 3Institute for Basic Science, Daejeon 305-881, Korea 4Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany As a national science project, the Korean government has recently established the Institute for Basic Science (IBS) with the goal of conducting world-class researches in medium-to-large scale basic sciences. One of the core facilities for the IBS will be the rare isotope accelerator which can produce high-intensity rare isotope beams to investigate fundamental properties of nature, and also to support a broad research program in the areas of material sciences, medical and biosciences, and future nuclear energy technologies. The construction of the accelerator is scheduled to be completed by around 2017. The design of the accelerator complex has been optimized to deliver high average beam currents on targets, and to maximize the production of rare isotope beams through the simultaneous use of Isotope Separation On-Line (ISOL) and In-Flight Fragmentation (IFF) methods. The proposed accelerator is, however, not indeed optimal for the high energy density sciences which usually require very high peak currents on the target. In this study, we present possible beam-plasma experiments that can be done within the scope of the current accelerator design, and also investigate possible future extension paths that may enable high energy density sciences with intense pulsed heavy ion beams. Work supported by Fermilab Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy

Speaker: Moses Chung (Fermi National Accelerator Laboratory)

11:40 → 13:20 Lunch (on your own)

13:20 → 14:35 Chamber, Technology, and Systems - Chair: E. Lee

13:20 The Current Development Status of Fluoride Salt Cooled High Temperature Reactor (FHR) Technology And its Overlap with HIF Target Chamber Concepts

R.O. Scarlat, P.F. Peterson Nuclear Engineering Department, UC Berkeley, Berkeley, California, 94720, USA The fluoride salt cooled high temperature reactor (FHR) is a class of fission reactor designs that use liquid fluoride salt coolant, TRISO coated particle fuel, and graphite moderator. Heavy ion fusion (HIF) can likewise make use of liquid fluoride salts, to create thick or thin liquid layers to protect structures in the target chamber from ablation by target x-rays and damage from fusion neutron irradiation. This presentation summarizes ongoing work in support of design development and safety analysis of FHR systems. Development work for fluoride salt systems with application to both FHR and HIF includes thermal-hydraulic modeling and experimentation, salt chemistry control, tritium management, salt corrosion of metallic alloys, and development of major components (e.g., pumps, heat exchangers) and gas-Brayton cycle power conversion systems. In support of FHR development, a thermal-hydraulic experimental test bay for separate effects (SETs) and integral effect tests (IETs) was built at UC Berkeley, and a second IET facility is under design. The experiments investigate heat transfer and fluid dynamics and they make use of oils as simulant fluids at reduced scale, temperature, and power of the prototypical salt-cooled system. With direct application to HIF, vortex tube flow was investigated in scaled experiments with mineral oil. Liquid jets response to impulse loading was likewise studied using water as a simulant fluid. A set of four workshops engaging industry and national laboratory experts are planned for the current year, with the goal of developing a technology pathway to the design and licensing of a commercial FHR. The pathway will include experimental and modeling efforts at universities and national laboratories, requirements for a component test facility for reliability testing of fluoride salt equipment at prototypical conditions, requirements for an FHR test reactor, and development of a pre-conceptual design for a commercial reactor. Supported by the DOE Office of Nuclear Energy NEUP program.

Speaker: Raluca Scarlat (UC Berkeley, Nuclear Engineering)

13:45 Liquid wall chambers for HIF

R. W. Moir Vallecitos Molten Salt Research [email protected] Livermore, California, 94550, USA Heavy Ion Fusion (HIF) energy releases are in the form of neutrons, X rays and target debris whose energy is about a GJ. Early on inventors suggested using liquid chambers without solid first walls because liquids unlike solids do not undergo radiation damage and vaporization of the liquid surface is acceptable. The form of the liquid is in a vortex oriented either horizontally or vertically with gas bubbles injected to help cushion the sudden expansion from the thermal spike. The spin rate of the vortex over comes gravity and forms a boundary between the liquid and the vacuum region inside of low enough vapor pressure to allow propagation of the beam to the target. The vortex can be a “rigid rotor” with the liquid containing solid walls mechanically rotated, in which case the liquid will tend to be quiescent or the vortex can be maintained by jets, injecting and extracting liquid, in which case there will be strong turbulence induced by shear flow. Other geometries considered were waterfalls and jets both stationary and oscillating. The liquids considered must contain lithium to breed tritium and they include: liquid lithium, a mixture of LiF+BeF2 called flibe, and a lithium-lead mixture. If strong magnetic fields are present for example from the magnetic focus system or intentionally imposed the liquid almost surely must be flibe owing to its low electrical conductivity thus reducing MHD affects. The frequency of producing micro explosions is set by the time the chamber can be cleared and ready for the next target to be injected and the beam to propagate to the target. X rays cause evaporation of liquid that has to be pumped and condensed. Neutrons cause liquid ejecta (spalled blobs of liquid) that need to be cleared. Design of liquid chambers depends strongly on the geometry of the target illumination and final focus system and therefore cannot be done independently but rather must be integrated with the entire plant design. Further, the design also depends strongly on the expected target yield and desired pulse rate. The speed of the liquid is limited to ~5 m/s for flibe and probably other liquids by erosion where it passes through inlet and outlet tubing. There is still the issue of radiation damage to components that “look” directly at the target that emits neutrons and other radiation such as the final focus magnets. However, these are usually further away (>5 m) from the neutron source than the first wall that is typically 1 to 2 m away. A serious problem threatens success of fusion power development and that is the development of a material to withstand this much closer and therefore stronger neutron flux for a long enough time to be of commercial interest. This problem is substantially avoided in HIF by use of liquid walls. Liquid walls of about 0.5 m thick of flibe or about 1 m for lithium or lithium-lead can reduce the neutron energies to those familiar to fission reactors and increase the predicted life of the structural components to the range of the life of the power plant.

Speaker: R. W. Moir (Vallecitos Molten Salt Research)

14:10 Economic Viability of Large-scale Fusion Systems

Charles E. Helsley Fusion Power Corporation, Scotts Valley, CA 95066 The utility industry has conditioned us to think in term of power generation facilities having capacities of about 1 Gigawatt (GW). This works for fossil fuel plants and for most fission facilities for it is large enough to support the sophisticated generation infrastructure but still small enough to be accommodated by most utility grid systems. The size of a fusion power system demands a different paradigm. The compression and heating of the fusion fuel for ignition requires a large driver even if it is necessary for only a few microseconds or nanoseconds per energy pulse. The economics of large systems, that can effectively use more of the driver capacity, need to be examined. Large output systems provide a problem for electrical grids for no grid node in the US can accept more that about 6 GW, yet the ideal duty cycle for a large driver, such as the Single RF Driver (SPRFD) system of FPC, is most economical when the output is large, say 30 GWe or more. This is incompatible with most regional grid structures and thus requires either grid reconstruction or some other means of using the large output. We have examined several cases in our financial models. One is a simple 'all electric model' and another is an electricity plus synthetic liquid fuel model. Each can produce potable water by multi-effect distillation (MED) processes where water is in high demand and a non-potable source of water is available. Other models might include major electricity users in the immediate vicinity, users such as smelters, metal refiners, etc. The assumptions used in our models are specific for the SPRFD process but could be generalized for any system. We assume that the accelerator is the most expensive element of the facility and estimate its cost to be $20 Billion. Chambers and fuel handling facilities are projected to cost $1.5 Billion each with up to 10 to be serviced by one accelerator. We have taken data from the literature for the cost of electrical generation facilities and synthetic liquid fuel production costs have been estimated in the Green Freedom report produced by LANL. The water maker costs come from IDE Technologies and Veolia's experiences in Bahrain and, although capable of paying for itself at irrigation rates, water generally contributes little to the overall profit of the facility. But it may be necessary to produce water as a means of utilizing the 'waste heat' in a way that minimizes environmental impact. Using these assumptions and data, we conclude that a fully utilized HIF system will produce marketable energy at roughly one half the cost of our current means of generating an equivalent amount of energy from conventional fossil fuel and/or fission systems. Even fractionally utilized systems – i.e. systems used at 25 percent of capacity, can be cost effective in many cases. Our conclusion is that SPRFD systems can be scaled to a size and configuration that can be economically viable and very competitive in today's energy market.

Speaker: Charles Helsley (Fusion Power Corporation)

14:35 → 17:15 Poster session

14:35 Advantages of the Single Pass RF Driver for Pellet Implosion and Ignition

Robert Burke Fusion Power Corporation Santa Cruz, CA 95060 The discovery of the heavy ion driver in 1975 was that the technology of high-energy particle accelerators already had the tools to design ICF drivers that meet all the requirements for fusion power production. The hitch was that heavy ion drivers would excel at driving fusion power plants, but they would not lend themselves to cheap demonstrations with sub-scale pellet experiments. This implied a new paradigm for power production with ICF: 1. The performance of new configurations of mainstream accelerators is predictable. 2. To reduce the level of risk to that needed by investors, the driver parameters need to be set above the threshold of confidence for prediction of pellet performance. Using conservative parameters, the essence of the second part of the paradigm, is the focus of the Single Pass RF Driver. Using 20MJ for Compression, SPRFD emphasizes achievable compression by using more energy than Basko to compress to the same density, 100g/cc. Reducing the spot on target ≥10x (by not using storage rings), SPRFD provides the 50µm focal spot needed for fast ignition of 100g/cc fuel with ρR = 0.5g/cc. By using isotopes for the Fast Ignition pulse whose range is ~1/7 that of the isotopes used to drive Compression, SPRFD reduces the Fast Ignition energy needed by Basko ~7x. The shorter-range component of the beam pulse also drives implosion of the end caps of the cylindrical target. For this, the duration of the shorter-range component of SPRFD’s beam is much longer than the time scale of fast ignition (~10 nsec vs. 0.1 nsec). Only the final part of the shorter-range pulse needs the peak power required for fast ignition. This peak power is ~7x less than that used by Basko’s cylindrical target. The 50µm spot also is available for compression, because neither pulse uses storage rings. SPRFD spirals the beam spot, like Basko, to follow the implosion, and the 50µm concentrates the heating closer to the interface between the absorber and pusher layers. The penultimate part of the shorter-range pulse burns a path through blow-off. This helps the final part of the pulse to get through the blow-off and get into and ignite the fuel that has the density needed to initiate propagating burn.

Speaker: Dr Robert Burke (Fusion Power Corporation)

14:35 All-Electron Path Integral Simulations of Warm Dense Matter: Application to Water and Carbon

K. P. Driver and B. Militzer University of California, Berkeley Berkeley, California, 94720, USA We develop an all-electron path integral Monte Carlo method with free-particle nodes for warm dense matter and apply it to water and carbon plasmas. We thereby extend path integral Monte Carlo studies beyond hydrogen and helium to elements with core electrons. Path integral Monte Carlo results for pressures, internal energies, and pair-correlation functions compare well with density functional theory molecular dynamics at lower temperatures of (2.5-7.5)×105 K, and both methods together form a coherent equation of state over a density-temperature range of 3-12 g/cm3 and 102-109 K. This work appears in Phys. Rev. Lett. 108, 115502 (2012). Supported by the NSF (DMS-1025370). Computational resources provided by the National Center for Atmospheric Research and Lawrence Berkeley National Laboratory.

Speaker: K. P. Driver (University of California)

14:35 Alternate Operating Scenarios For NDCX-II*

W. M. Sharp, A. Friedman, D. P. Grote, R. H. Cohen, S. M. Lund Lawrence Livermore National Laboratory Livermore, California, 94550, USA J.-L. Vay, W. L. Waldron, A. Yuen Lawrence Berkeley National Laboratory Berkeley, California, 94720, USA NDCX-II is a newly completed accelerator facility at LBNL, built to study ion-heated warm dense matter and aspects of ion-driven targets for inertial-fusion energy. The baseline design calls for using twelve induction cells to accelerate 40 nC of Li+ ions to 1.2 MeV. During commissioning, though, we plan to extend the source lifetime by extracting less total charge. For operational flexibility, the option of using a helium plasma source is also being investigated. Over time, we expect that NDCX-II will be upgraded to substantially higher energies, necessitating the use of heavier ions to keep a suitable deposition range in targets. Each of these options requires development of an alternate acceleration schedule and the associated transverse focusing. The schedules here are first worked out with a fast-running 1-D particle-in-cell code ASP, then 2-D and 3-D Warp simulations are used to verify the 1-D results and to design transverse focusing. *Work performed under the auspices of US Department of Energy by LLNL under Contract DE-AC52-07NA27344 and by LBNL under Contract DE-AC03-76SF00098.

Speaker: W. M. Sharp (Lawrence Livermore National Laboratory)

14:35 Can FPC's Single-Pass RF Driver Produce a 50 µm Spot Size for Fast Ignition?

Alex Burke Fusion Power Corporation / SAIC Palo Alto, CA 94306 The design of the Single-Pass RF Driver (SPRFD) is similar to four HIDIF-type drivers in parallel. A significant difference in SPRFD is the absence of HIDIF's multi-turn injection storage rings, thereby avoiding the ~10-fold dilution of transverse phase space that occurs during this process. Instead, SPRFD uses patent-pending methods to accomplish longitudinal beam compression, while preserving a low transverse emittance. Preliminary calculations, based on HIDIF's beam parameters and estimated emittance prior to the storage rings, suggest that SPRFD's final spot-size could be as low as 50 µm. A spot size of 50 µm would be very attractive for fast-ignition schemes, especially with a cylindrical target design. The aim of the present study is to examine all factors contributing, or potentially contributing, to the magnitude and growth of beam emittance in the SPRFD system up to the target itself, in order to validate the 50 µm prediction. This will include the use of particle simulation codes such as Warp and MICHELLE, as well as established theoretical models of beam stability and neutralization. A realistic environment inside FPC’s industrial fusion power chamber will be considered, especially with regard to neutralization effects by ambient vapor. The possible benefits of injected plasma neutralization will be assessed. Analysis of final transport and focusing will include interpenetrating multi-species beams as specified by the SPRFD design. Various target irradiation symmetries will be considered. Progress will be reported on the goal of parametric analysis of sensitivities for reliably achieving a 50 µm spot size, at the precise location specified by the tracking system’s observation of targeting reticules on the injected lithium sabots that house the fuel pellets.

Speaker: Alex Burke (Fusion Power Corp / SAIC)

14:35 Development of a User-Facility Plan for NDCX-II

M. E. Koepke Physics Department, West Virginia University Morgantown, West Virginia, 26506-6315, USA The second Neutralized Drift Compression Experiment (NDCX-II) will enable enhanced experiments in warm dense matter (WDM) and aspects of ion-driven target physics for inertial fusion energy (IFE). These experiments are relevant to processes in the interiors of giant planets and to the accelerator and high-energy-density (HED) science underpinning the concept of heavy-ion fusion. There is a perceived need to cultivate the development of a facility-user population on NDCX-II as a feature of future grant applications for facility support from the Department of Energy Office of Science. HED/IFE science solicitations in 2013 are aimed at universities and DOE laboratories. The development of a user-facility plan for NDCX-II is being carried out over the next 12 months, toward the goal of developing the user-base dimension (concept, policy, targeted groups both national and international), drawing upon experience with other-Lab user-facility models. Progress will be presented. NDCX-II schedule-allocation categories may include facility maintenance and development, IFE-motivated science studies, and basic HED science, WDM, and beam science studies. A possible set may be: 1. Experiment time, i.e., “beam time” 2. Facility beam-scientist time, i.e., liaison support between a user and the facility 3. Beam-physics and beam-engineering studies to advance facility optimization 4. Scheduled and unscheduled facility maintenance 5. User-customized beam-line and/or target-chamber reconfiguration 6. Diagnostics 7. Target fabrication Prioritization (schedule flexibility) and allocation (schedule fraction) will evolve during the progressive transformation of NDCX-II from a facility for collaborative experiments in which external users work closely with scientists and engineers of NDCX-II into a facility that is increasingly used by independent users. The NDCX-II facility itself, the NDCX-II operational regimes, and the beam-enabled science and technology will contribute to the portfolio of anticipated experimental and theoretical effort. As a user facility, NDCX-II could field additional diagnostic capabilities in a collaboration of external users and NDCX-II staff scientists and engineers and could facilitate independent external users who compete for beam time and require a site-provided suite of diagnostic capabilities. NDCX-II could expand its user-facility identity as the user-community expertise, enthusiasm, and demand develop and as the NDCX-II capabilities expand, become documented quantitatively, and become familiar to a wider set of users. Supported by USDOE FES through a subcontract with Lawrence Berkeley National Lab.

Speaker: Mark Koepke (West Virginia University)

14:35 Electro-magnetically driven shock and dissociated hydrogen target for stopping power measurement

K. Kondo, T. Moriyama (1); J. Hasegawa, K. Horioka (2); and Y. Oguri(1) (1) Research Laboratory for Nuclear Rectors, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 JAPAN (2) Department of Energy Sciences, Tokyo Institute of Technology 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 JAPAN For ion-driven warm dense matter experiments and heavy ion fusion target design, the stopping power is an important issue. Stopping power depends on the chemical state of target material. Very few studies have been published for change of stopping power due to chemical effects[1]. Therefore, it is of interest to experi-mentally examine the change of stopping power of hydrogen due to transition from molecular state to dissociated atoms. Electro-magnetic pulse device with 15 kV discharge voltage and with 1kPa initial molecular hydrogen gas pressure generated shock wave[2]. The shock speed was estimated as 30 km/s by shadowgraph method. Behind the shock front, there was dissociated hydrogen gas region without ionization which was suitable for the stopping power measurement. However, the previous experiments show that target durations as long as some microseconds is required for synchronization with ion beams. For this improvement, optimization of new electrode configuration is under way. We will discuss the dissociated hydrogen gas property obtained with the new device for the stopping power measurement considering the measured shock speed. References [1] D. Semrad, Phys. Rev. A, 58, 5008 (1998). [2] J. Hasegawa, et al., Nucl. Instrum. and Methods A, 606, 205-211 (2009).

Speaker: K. Kondo (Research Laboratory for Nuclear Rectors)

14:35 Evaluation of Transport Properties in Warm Dense State by using Isochoric Pulsed-power Discharges

Yasutoshi Miki, Hirotaka Saito, Takuya Takahashi, Toru Sasaki, Takashi Kikuchi, and Nob. Harada Nagaoka University of Technology Kamitomioka 1603-1, Nagaoka, Niigata, 940-2188, Japan Warm dense matter (WDM) is of key interest to understand the formation of plasma from a solid state, interior of giant planets, hydrodynamics of fuel pellet in inertial confinement fusion, and so on. WDM state is defined by density from 10-3 ρs (ρs is the solid density of matter) to 10ρs, and temperature from 0.1 to 10 eV. The characteristics of WDM are hard to study theoretically from first principle approach. On the other hand, to create and to characterize properly the WDM condition are difficult in a laboratory. In this study, we evaluate the transport properties in WDM state by using pulsed-power discharge with isochoric heating [1-2]. The pulsed-power discharge is generated by a gap switch and low inductance capacitors (3×1.87 μF) charged up to about 15 kV. The stray inductance of the discharge device was estimated to be 165 nH from the preliminary experiment with the short-circuit. The features of the method are possible to produce an isochoric condition, use of a conventional tamper, avoiding skin effect, and direct spectroscopic measurement. To achieve isochoric heating, copper foam, which has pores from 50 μm to 600 μm of porous sizes and about 90 % porosity, was packed into a sapphire hollow capillary (φ5×10 mm). To avoid the creepage on surface sapphire, turbo-molecular and rotary pumps are set at bottom of the chamber. The interior pressure of the chamber is set to be less than 10-3 Pa. The density of WDM can be controlled by enclosed volume of copper foam. The temperature of generated WDM was several thousand Kelvin estimated by the emission spectrum and the input energy history with SESAME equation of state [3]. Observed electrical conductivity and foam/plasma temperature is about 104 S/m and 4000 K in 0.1ρs. The observed electrical conductivity is in agreement with the other experimental results and predictions. The temperature dependence of electrical conductivity is neither metallic nor ideal plasma characteristics. We will also discuss the estimation of thermal transport in WDM state [4] in this conference. This work was partly supported by Grant-in-Aid for Young Scientists (B) from Japan Society for the Promotion of Science (23740406). [1] Y. Amano, et. al., The Seventh Conference on Inertial Fusion Sciences and Applications (IFSA 2011), P.We_85, p.260 (2011). [2] Y. Amano, et. al., Submitted to Rev. Sci. Instrum. [3] S. P. Lyon, J. D. Johnson, T-1 Handbook of the SESAME Equation of State Library, LA-CP-98100 (1998). [4] T. Sasaki, et. al., Submitted to IEEE Plasma Sciences.

Speaker: Yasutoshi Miki (Nagaoka University of Technology)

14:35 Experimental investigation of heavy ion energy loss in dense plasma, generated by laser induced soft X-rays

A. Ortner, D. Schuhmacher, A. Frank, S. Faik, D. Kraus, F. Wagner, W. Cayzac, A. Blazevic, G. Schaumann, M.M. Basko, An. Tauschwitz, V. Bagnoud, M. Roth Institut für Kernphysik, Technische Universität Darmstadt, Germany GSI-Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany We report on heavy ion energy loss experiments in dense carbon plasma heated by hohlraum generated X-rays. The energy deposition of ions in plasmas is a key question in ICF simulations, for the evaluation of heavy ions as drivers and for research in the realm of ion driven fast ignition concepts. The GSI Helmholtzzentrum für Schwerionenforschung offers the unique possibility to use the high energy laser system PHELIX to create dense laser plasmas and to probe this with a heavy ion beam from the UNILAC accelerator. With direct laser heating of thin carbon foils, fully ionized plasma with a temperature of up to 200 eV and a maximum electron densities of 1021 cm-3 can be created [1]. To reach higher plasma densities the foil has to be heated with intense X-rays. By converting laser light (150 J, 1.5 ns, 527 nm) in a spherical gold hohlraum (600 µm diameter) soft X-rays with radiation temperature of 100 eV are generated. These are transported into a secondary cylindrical hohraum where they heat two 100 µg/cm2 carbon foils. With this method we are able to create carbon plasmas with an electron density of 1022 cm-3 and an ionization degree of 4. These targets have been fabricated and characterized at the Detector- and Target laboratory of Darmstadt University. The radiation temperatures in the primary and the secondary hohlraum as well as the plasma conditions were characterized [2] and compared with 2D-hydro simulations (RALEF 2D, [3]) and theoretical predictions [4]. In the first energy loss experiments with a Ca17+ ion beam with 4 MeV/u we observed an increase of the stopping power of up to 40%. [1] A. Frank, A. Blazeiv et al. Energy loss of argon in a laser-generated carbon plasma. Phys. Rev. E, 81(2):026401, 2010 [2] T. Hessling, A. Blazevic et al. Time and spectrally resolved measurements of laser-driven hohlraum radiation, Phys. Rev. E, 84:016412, 2011 [3] M.M. Basko, J. Maruhn et al. An efficient cell-centered diffusion scheme for quadrilateral grids. J.Comput. Phys., 228:2175-2193, 2009 [4] G.D. Tsakiris, et al. Energy distribution in cavities by thermal radiation. Phys. Fluids B, 4:992-1005, 1992

Speaker: Alex Ortner (GSI Darmstadt)

14:35 Experimental Verification of Stop-Band Distributions in Doublet Focusing Channels

K. Fukushima, K. Ito, H. Okamoto, S. Yamaguchi, K. Moriya, H. Higaki, T. Okano Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan S. M. Lund Lawrence Livermore National Laboratory, Livermore, California 94550, USA P. A. Seidl Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA Almost all modern particle accelerator systems exploit the principle of strong focusing. Not only focusing but also defocusing forces are employed there, so that we can spatially confine a large number of charged particles more effectively than the case where only focusing forces are used. Needless to say, the most standard strong focusing channel is the so-called “doublet (or in other words, FODO lattice)” in which the beam receives linear focusing and defocusing forces alternately. Doublets have been very often adopted for beam transport channels and linear accelerators including a possible heavy ion fusion driver and common drift tube linacs. A non-scaling fixed field alternating gradient ring also consists of many doublet cells. These facts indicate practical importance of understanding the collective nature of high-quality hadron beams traveling in long doublet channels. While we can find a number of numerical and analytic works on this subject in past literature, little has been done experimentally. In the present work, we investigate the dynamical property of doublet focusing by employing a compact linear Paul trap system. Since the collective motion of a non-neutral plasma in the trap is physically almost equivalent to that of a charged-particle beam in strong focusing channels, we can use the former to study the latter. We here systematically explore the stability of ion beams focused by a series of doublets, changing the waveform of the plasma confinement field over a wide range. It is shown that a few stop bands of coherent resonance appear depending on the beam intensity. When there is an imbalance between the horizontal and vertical focusing, those stop bands split. The experimental observations are compared with WARP simulation results. Supported in part by a Grant-in-Aid for Scientific Research, Japan Society of the Promotion of Science.

Speaker: Kei Fukushima (Graduate School of Advanced Sciences of Matter, Hiroshima University)

14:35 Generation of Multi-charged High Current Ion Beams using the SMIS 37 Gas-dynamic Electron Cyclotron Resonance (ECR) Ion Source

M.A. Dorf (1); V.G. Zorin, A. V. Sidorov, A.F. Bokhanov, I.V. Izotov, S.V. Razin, and V.A. Skalyga (2) (1) Lawrence Livermore National Laboratory, Livermore, California, 94550 USA (2) Institute of Applied Physics RAS, 46 Ulyanov St., 603950 Nizhny Novgorod, Russia A gas-dynamic ECR ion source (GaDIS) is distinguished by its ability to produce high current and high brightness beams of moderately charged ions. Contrary to a classical ECR ion source where the plasma confinement is determined by the slow electron scattering into an empty loss-cone, the higher density and lower electron temperature in a GaDIS plasma lead to an isotropic electron distribution with the confinement time determined by the prompt gas-dynamic flow losses. As a result, much higher ion fluxes are available, however a decrease in the confinement time of the GaDIS plasma lowers the ion charge state. The gas-dynamic ECR ion source concept has been successfully realized in the SMIS 37 experimental facility operated at the Institute of Applied Physics, Russia. The use of high-power (~100 kW) microwave (37.5 GHz) radiation provides a dense plasma (~1013 cm3) with a relatively low electron temperature (~50-100 eV) and allows for the generation of high current (~1 A/cm2) beams of multicharged ions. In this work we report on the present status of the SMIS 37 ion source and discuss the advanced numerical modeling of ion beam extraction using the particle-in-cell code WARP. Supported by USDOE contract no. DE-AC52-07NA27344; Russian Foundation for Basic Research (RFBR), grant n0. 11-02-97056-r_povolzhie_a; Federal Targeted Program "Scientific and Educational Personnel of the Innovative Russia" for 2009-2013; President of the Russian Federation for young candidates of science grant n0. MK-4743.2012.2.

Speaker: M. A. M. A. Dorf (Lawrence Livermore National Laboratory)

14:35 Harmonic analysis of irradiation asymmetry for cylindrical implosions driven by high-frequency rotating ion beams

A. Bret (1,2,3); A.R. Piriz (1,2); and N.A. Tahir (4) (1) Universidad de Castilla–La Mancha, Ciudad Real, Spain (2) Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Ciudad Real, Spain (3) Harvard CfA, Cambridge, MA (4) GSI Darmstadt, Germany Cylindrical implosions driven by intense heavy ion beams should be instrumental in the near future to study high-energy-density matter. By rotating the beam by means of a high-frequency wobbler, it should be possible to deposit energy in the outer layers of a cylinder, compressing the material deposited in its core. The beam’s temporal profile should, however, generate an inevitable irradiation asymmetry likely to feed the Rayleigh-Taylor instability (RTI) during the implosion phase. We compute the Fourier components of the target irradiation in order to make the connection with previous works on the RTI performed in this setting. Implementing one- and two-dimensional beam models, we find that these components can be expressed exactly in terms of the Fourier transform of the temporal beam profile. If T is the beam duration and Omega its rotation frequency, “magic products” Omega*T can be identified which cancel the first harmonic of the deposited density, resulting in an improved irradiation symmetry. A. Bret, A.R. Piriz, and N.A. Tahir, Physical Review E 85, 036402 (2012)

Speaker: A. Bret (Universidad de Castilla)

14:35 Heavy Ion Beam Acceleration in the KEK Digital Accelerator: Induction Acceleration from 200 keV to a few tens of MeV

T. Yoshimoto (1,3); Y. Barata (2,3); T. Iwashita (3); S. Harada (2,3); D. Arakawa, T. Arai, X. Liu1 (3); T. Adachi (3,4); H. Asao (5); E. Kadokura, T. Kawakubo, T. Kubo (3); K.W. Leo (3,4); H.Nakanishi (3); Y. Okada (5); K. Okamura (3.4); K.Okazaki (6); H. Someya (3); K. Takayama (1,2,3,4); and M. Wake (3) (1) Tokyo Institute of Technology, Nagatsuta, Kanagawa, Japan (2) Tokyo City University, Todoroki, Tokyo, Japan (3) High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan (4) Graduate University of Advanced Studies, Hayama, Kanagawa, Japan (5) NEC Network-Sensor, Futyu, Tokyo, Japan (6) Nippon Advanced Technology Co. Ltd. (NAT), Tokaimura, Ibaraki, Japan Since the last year beam commissioning in the KEK digital accelerator [1], which is the small scale induction synchrotron, has been carried out using He1+ ion beam of a few tens of μA [2].This paper discusses essential and crucial issues associated with induction acceleration of a low current ion beam from a low energy, such as injection error, relatively large closed orbit distortion (COD), and induction acceleration with predicted feedback. Injection errors are categorized into injection orbit mismatching and optics mismatching. The former is observed as a coherent betatron oscillation, which is corrected by adjusting two pairs of steering magnets. The COD, which is monitored at 5 positions along the ring, is corrected by 8 figure back leg coils of the main magnets [1]. Induction acceleration and barrier bucket trapping are controlled by a gate control system of the switching power driving the induction cells, which consists of the bunch monitor, FPGAs, and DSP. In acceleration in a rapid cycle synchrotron, acceleration timing is quite important. Unfortunately the gate control based on direct beam-feedback is not available because of a poor S/N ratio in the bunch monitor signal. So, the timing for acceleration pulse trigger is scheduled in advance in the FPGA. This is called a predicted control method [3]. We discuss in details how the trigger timing of acceleration/trapping voltage pulse is determined so as to well synchronized with magnet ramping. Observed beam motions are reproduced with a help of computer simulations. Then, the predicted control method will be justified. [1]T. Iwashita et al., “KEK Digital Accelerator”, PHY.Rev.ST-AB14, 071301-20 (2011) [2]K. Takayama, in this conference. [3]S. Harada, in Master Thesis (Tokyo City University) 2012.

Speaker: T. Yoshimoto (Tokyo Institute of Technology)

14:35 HVDC Dynamitron® for the Multi-Beam Single Pass RF Driver

Richard A. Galloway and Marshall R. Cleland IBA Industrial Inc. 151 Heartland Blvd. Edgewood NY, 11717 Each of the 16 front ends in the HIDIF design study used 50kV extraction and 150kV HVDC, on three separate ions sources, to launch a timed set of the isotopic pulses into three separate low energy beam transport lines, which converge into a 3-way, switching magnet, and emerge in series on a single beamline to the radiofrequency quadrupole. While the format of the Single Pass RF Driver is mainly four HIDIF linacs in parallel, the 16 sources in each front end are integrated into a compact array and mounted in the terminal of a ~1.5MeV Dynamitron®. Pierce-geometry extraction electrodes are integrated into the 1.5MV column, adding multiple isotopes to the high-brightness 1.5MeV front end demonstrated at the Argonne National Laboratory (ANL) 1976-80 (Watson, Nuc. Sci., 1979). Where ANL put a magnetic triplet in the re-entrant geometry of the HVDC ground electrode, SPRFD puts the upstream end of the multi-channel RFQ. This close coupling avoids transporting low-energy, space-charge dominated beams, and simplifies the multi-isotope Front Ends for power producing fusion systems, which do not need the flexibility of research systems. RFQ’s can circumvent the practical issues of MV preaccelerators, but high beam current is crucial for HIF drivers; the (βγ)5/3 scaling of the transport limit for space-charge-dominated beams provides an important factor for 1.5MeV vs. 200keV. HIF drivers need both MV preacceleration and the RFQ. The nominally 1.5 MV Dynamitron® is programmed to output all isotopes at the same velocity, as needed by the RFQ. High vacuum is maintained by exploiting the pulsed nature of the beams to minimize gas load, and by providing large holes in the high voltage electrodes to maximize conductance to the pumps at electrical ground. For each ignition sequence, ten of the sources produce ~20 µsec of beam and the other 6 produce ~10µsec each. Including the ~100µsec gap between these groups of isotopes, with the driver producing 10 pps, the entire source array has a duty factor ~0.004, with only one source emitting beam at any one time. Means to provide gas puffs include fast valves, laser heating (with or without laser ionization), and field emission sources that use hollow needles containing liquid such as Hg. Capitalizing on the low duty factor of the sources also is an effective means to minimize the power that must be supplied to the 1.5 MV terminal to operate the sources. The timed sequence of the individual isotopes means that the beam current accelerated by the Dynamitron® is that of a single isotope, i.e., ≥100mA. Allowing ~150kW for the power during each pulse of the SPRFD, the ~0.004 duty factor results in an average power of ≤1kW—far below the Dynamitron®’s capability.

Speaker: Richard A. Galloway (IBA Industrial Inc.)

14:35 International Shock-Wave data base

I.V. Lomonosov(1); K.V. Khishchenko, P.R. Levashov, Dmitry V. Minakov, A.S. Zakharenkov, V.E. Fortov (2), and J.B. Aidun (3) (1) IPCP RAS, Chernogolovka, Moscow reg., 142432, RUSSIA (2) JIHT RAS, Izhorskaya str. 13 bldg 2, 125412, Moscow, RUSSIA (3) SNL, Albuquerque, NM 87185, USA* In this work, we announce the start of a new project: International Shock-Wave data base (ISWdb). Shock-wave and related dynamic material response data serve for calibrating, validating, and improving material models over very broad regions of the pressure–temperature–density phase space. Measurements of principal, reflected and porous Hugoniots, and determinations of release isentrope parameters cover a broad range of the phase diagram. This unique information embraces nine orders with respect to pressure and five orders with respect to density. All of the data are unique, have their own history and result from complicated expensive experiments. As a follow-on to our current on-line database (http://www.ficp.ac.ru/rusbank/), the ISWdb will include the approximately 20000 experimental points on shock compression, adiabatic expansion, measurements of sound velocities behind the shock front and free-surface-velocity profiles for more than 650 substances that we previously collected. The ISWdb project objectives are: (i) to develop a database on properties of materials under conditions of shock-wave and other dynamic loadings, selected related quantities of interest, and the meta-data that describes the provenance of the measurements and material models; and (ii) to make this database available internationally through the Internet, in an interactive form. The development and operation of the ISWdb will be guided by an advisory committee. The database will be installed on two mirrored web-servers, one in Russia and the other in USA. The database will provide access to original experimental data on shock compression, non-shock dynamic loadings, isentropic expansion, measurements of sound speed in the Hugoniot state, and time-dependent free-surface or window-interface velocity profiles. Users will be able to search the information in the database and obtain the experimental points in tabular or plain text formats directly via the Internet using common browsers. It will also be possible to plot the experimental points for comparison with different approximations and results of equation-of-state calculations. The user will be able to present the results of calculations in text or graphical forms and compare them with any experimental data available in the database. Our goal is to make the ISWdb a useful tool for the shock-wave community. This talk is intended to solicit your feedback and interest in submitting your experimental results to the ISWdb, as well as present an overview of the project. *Sandia National Laboratories (SNL) is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Speaker: I. V. Lomonosov (IPCP RAS, Chernogolovka)

14:35 Ion Sources for the Multi-Isotope Single-Pass RF Driver

Ian G. Brown (1) and Robert Burke (2) (1) Berkeley Scientific, Berkeley, CA 94708 (2) Fusion Power Corporation, Santa Cruz, CA 95060 The Front Ends of the Single-Pass RF Driver (SPRFD) produce a timed sequence of many different isotopes: 10 with mass ~Xe for the Compression pulse and 6 with mass ~Pb for Fast Ignition and implosion of the pellets’ cylindrical end caps. The16 isotopes require practical, existing ion source technology. Practical considerations include compatibility with the requirements for vacuum and support (e.g., electric power and cooling) that can be provided to the sources in the ~1.5MV terminal, and compactness for produce-ability of the electrodes and ceramics of the HVDC column. The ion sources needed for the SPRFD are within the state of the art in terms of brightness, current, and engineering features. Xenon isotopes, for example, use the technology Hughes Research Laboratories derived from ion thrusters for the demonstration at Argonne National Laboratory (1977-80) of over 60 mA at low-emittance, 1.5MeV Xe+. At that time, the primary issue for scaling to ≥100 mA was the ability to transport the space charge-dominated beams after their emission from the high-gradient accelerating column in the 1.5 MV Dynamitron®. Demonstration of the radiofrequency quadrupole accelerator (RFQ) by the Los Alamos National Laboratory, also in the late 1970s, provided the means to handle ≥100mA beams of 1.5 MeV heavy ions. Numerous RFQ applications have exploited the convenience of starting RF acceleration at low ion speeds while circumventing the practical issues of MV preaccelerators. For HIF drivers, however, the contribu-tion of high gradient d.c. acceleration to generating beams with ≥100mA needs to be exploited by combining the RFQ with MV+ pre-acceleration. To hold voltage in the high-gradient HV column, the gas load emanating at 1.5 MV needs to be evacuated with pumps located at electrical ground. With many ion sources, and gas load tending to increase with beam current, minimizing the gas load from each source is a first priority. The ~20 µsec on-time for each isotopic pulse allows pulsing the gas for the sources. At SPRFD’s 10 pps repetition rate, the duty factor for each source is ~0.0005, ~0.005 for the array of 10 sources ~Xe and less for the 6 sources ~Pb. Means to provide gas puffs include fast valves and laser heating, with or without laser ionization of the material. Very high brightness source technology using field emission from hollow needles containing liquid also may be appropriate for Hg, Bi, Pb, and other readily liquefied materials. Capitalizing on the pulsed nature and low duty factor of the sources also is an effective path to minimizing the power needed to run the sources in the 1.5 MV terminals.

Speaker: Ian G. Brown (Berkeley Scientific)

14:35 Kicker Magnets and Modulators for Single-Pass RF Driver HIF

Richard Cassel Stangenes Industries Incorporated Palo Alto, CA Kicker magnets are used in the beam manipulations in the Single Pass RF Driver (SPRFD) HIF, which combine the beam output from the ion sources to the fuel target. Kicker magnets are used in a set of converging beamlines that align the parallel beams from the injection RFQs into a common beam line. Then a coiled delay line, in which the beam is switched out by kickers after each turn of the coil delay line and back, further compress the beams. The incoming and delayed beams are separated into four parallel beam lines using additional kicker magnets. Finally, kicker magnets are used to direct the beams into two sides of the fuel target. Kicker magnet design factors include field strength, good field volume, switch times, and waveform control. Optimization trade-offs regarding cost involve bore dimensions v. magnetic field quality are needed. The type of the kicker magnets for their various uses will be described and assessed in light of existing magnet and modulator practice. The paper also will review the state of the art of kicker magnet applications, as relevant to the needs of the SPRFD

Speaker: Richard Cassel (Stangenes Industries Incorporated)

14:35 Magnetic Control of Laser Ablation Plasma for High-flux Ion Injectors

S. Ikeda, M. Nakajima, J.Hasegawa, T.Kawamura and K. Horioka Department of Energy Sciences, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midoriku, Yokohama 226-8502, Japan We investigated the interaction of a laser ablation plasma with a longitudinal magnetic field, intending to create a directional moving plasma for development of high-flux and low-emittance ion injectors [1]. The laser ablation plasma expands adiabatically and evolves to a collisionless moving plasma from a dense collision dominated state through an intermediate relaxation region in the magnetic field. The multi scale interaction processes between such plasma and longitudinal magnetic field have not been quantitatively well understood. To deepen our understanding of the plasma dynamics, we have started an interaction experiment of the laser ablation plasma with longitudinal magnetic field [2]. We produced the plasma by Nd:YAG laser (~ 109 W/cm2 ) irradiation on copper surface in a longitudinal magnetic field. The magnetic field was generated by a solenoidal coil, 10 mm in diameter and 30 mm in length. We measured the plasma flux and its transverse distribution at 17 cm from the target by a biased Faraday cup as a function of the magnetic field up to 0.2T. The charge state distribution of the plasma was measured with an ion energy analyzer. The results show that, in the presence of magnetic field, the ion current density increases about 5 times in the forward direction and the transverse distribution becomes shaper. These results indicate that the ion current density and its distribution can be controlled by moderate (~0.2T) magnetic field. We also observed that, in case of magnetic filed application, the plasma flux has two peaks and the first peak is composed of highly charged ions. This means the magnetic field can preferentially increase highly charged ions in the ablation plasma. [1] M. Okamura, A. Adeyemi, T. Kanesue, J. Tamura, K. Kondo et al., Rev. Sci. Instrum. , 81, 02A510 (2010) [2] S. Ikeda, M. Nakajima and K. Horioka, Plasma and Fusion Research, Vol.7, 1201215 (2012)

Speaker: S. Ikeda (Department of Energy Sciences, Tokyo Institute of Technology,)

14:35 Manipulations for delivering HIF beams onto targets: (1) Smoothing by arc wobblers, (2) Differential acceleration in final beam lines

A. Friedman LLNL, Livermore CA 94550 USA and Heavy Ion Fusion Science Virtual National Laboratory We describe two techniques related to the delivery of the ion beams onto the target in a Heavy Ion Fusion power plant. (1) By manipulating a set of ion beams upstream of a target, it is possible to achieve a more uniform energy deposition pattern. We consider an approach to deposition smoothing that is based on rapidly “wobbling” each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression [A. Friedman, Phys. Plasmas 19, 063111 (2012)]. Uniformity is achieved in the time-averaged sense; the oscillation period must be sufficiently shorter than the target’s hydrodynamic response timescale . This work builds on two earlier concepts: elliptical beams [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)]; and beams wobbled through full-circle rotations [e.g., R. C. Arnold, et al., Nucl. Instr. and Meth. A 199, 557 (1982)]. Arc-based smoothing remains usable when the geometry precludes full-circle wobbling, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some distributed-radiator targets. (2) By accelerating some beams “sooner” and others “later,” it is possible to simplify the beam line configuration in a number of cases. For example, the time delay between the “foot” and “main” pulses can be generated without resorting to large arcs in the main-pulse beam lines. This may minimize beam bending, known to be a source of emittance growth in space-charge-dominated beams. It is also possible to arrange for the simultaneous arrival on target of a set of beams (e.g., for the foot-pulse) without requiring that their path lengths be equal. This may ease a long-standing challenge in designing a power plant, in which the tens or hundreds of beams entering the chamber all need to be routed from one or two multi-beam accelerators or transport lines. Work performed under auspices of U.S. DoE by LLNL under Contract DE-AC52-07NA27344.

Speaker: Alex Friedman (LBNL)

14:35 Numerical Study of Heavy-Ion Stopping in Foam Targets with One-Dimensional Subcell-Scale Hydrodynamic Motions

Y. Oguri1, K. Kondo1, and J. Hasegawa2 1Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama 2-12-1-N1-14, Meguro-ku, 152-8550 Tokyo, Japan, 2Department of Energy Sciences, Tokyo Institute of Technology, Nagatsuta-cho 4259-G3-35, Midori-ku, 226-8502 Yokohama, Japan When designing parameters of ion-driven warm dense matter experiments with low-density foam targets[1], the foams are usually regarded as homogeneous media. For more detailed design, initial inhomogeneous porous structure of the foam target should be taken into account, since the mass stopping power of heavy projectiles can change with the target density and temperature[2]. In this regard, heavy-ion stopping in foam targets with subcell-scale hydro motions was numerically investigated. To simulate porous foam targets, we employed a simple 1D periodic multilayer model consisting of thin solid slabs and voids between them. The averaged pore diameter and cell-wall thickness of the foam were represented by the gap width between the slabs and the slab thickness, respectively. The electronic state of target atoms were approximated by a finite-temperature Thomas-Fermi model with given Wigner-Seitz radii. The density- and temperature-dependent stopping cross sections were evaluated using a binary encounter model. We tested a combination of Na (Z1 = 11) projectiles and subrange Al (Z2 = 13) foam targets with ρ ≈ 0.01−0.1ρsolid. The incident projectile energy was adjusted so that the Bragg peak was roughly at the center of the target. The hydrodynamic motion of the multilayer target was calculated with a 1D code MULTI[3]. Macroscopic hydrodynamic response of the foam was similar to that of a homogeneous target with the same mass thickness. Before homogenization by hydro motion, the total projectile energy loss in the foam target was smaller than that in the homogeneous equivalent. During homogenization, hot dense spots appeared at the positions where the pores (gaps) originally existed, owing to stagnation of the blow-off materials. As a result, even after the pores are filled with the blow-off materials, the initial inhomogeneity was not completely smeared out and the total energy loss in the foam target was still not equal to that in the homogeneous equivalent. References: [1] J.J. Barnard, J. Armijo, D.S. Bailey, A. Friedman, F.M. Bieniosek, E. Henestroza, I. Kaganovich, P.T. Leung, B.G. Logan, M.M. Marinak, R.M. More, S.F. Ng, G.E. Penn, L.J. Perkins, S. Veitzer, J.S. Wurtele, S.S. Yu and A.B. Zylstra, Nucl. Instr. and Meth. A 606 (2009) 134. [2]S. Skupsky, Phys. Rev. A 16 (1977) 727. [3]R. Ramis, R. Schmalz and J. Meyer-ter-Vehn, Comput. Phys. Commun. 49 (1988) 475.

Speaker: Y. Oguri (Research Laboratory for Nuclear Reactors)

14:35 Rarefaction Waves in Van Der Waals Fluids

Albert Yuen (1,2); John Barnard (3); Richard More (1) (1) Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA (2) University of California, Berkeley, California, 94720, USA (3) Lawrence Livermore National Laboratory, Livermore, California, 94550, USA As the simplest description of material that exhibits a liquid- vapor two-phase state, the Van der Waals' fluid model can be used to obtain qualitative (and sometimes quantitative) information about the fluid dynamics of material in the two-phase regime. We apply the general one-dimensional self-similar solution of a rarefaction wave in an initially semi-infinite liquid, uniform in temperature and density, to the specific case of a Van der Waals' fluid. Using dimensionless variables, we obtain a set of profiles for the fluid density, temperature and velocity, that describes the fluid for a wide range of space, time, initial conditions, and Van der Waals' parameters. These dimensionless results may be used to interpret experiments in which a material is rapidly isochorically heated before expanding. In particular, ``plateaus'' in temperature, density and velocity as a function of position are observed characterizing entrance into the two-phase regime. We observe that these “plateaus” - as well as the maximum fluid velocities, the densities and the temperatures of the liquid before entering the two-phase regime - depend exclusively on the initial entropy. Based on this set of universal dimensionless curves and the observed “plateaus”, we propose a semi-analytical method to determine the Van Der Waals parameters, the initial temperature and pressure from a single density profile recorded during the expansion.

Speaker: Albert Yuen

14:35 Single Pass RF Driver (SPRFD) Chamber Considerations

Charles Helsley Fusion Power Corporation, Scotts Valley, CA The primary functions of a chamber are fivefold: maintain vacuum integrity, contain the heat exchange working fluid, provide entry ports for beams, coolant and fuel pellet, provide structural containment and additional neutron shielding, and finally it must contain and facilitate extraction of the tritium produced during the reaction of neutrons with the working fluid. Each functions comes with constraints and the sum of these constraints that makes up the specifications for the chamber. We have placed neutron moderation and beam access as the first and second conditions for without them there is no fusion reaction and the rest of the chamber function is meaningless. The SPRFD system uses four beams that approach the target through a set of ports that are 180 degrees apart. The HILIFE II Reference Point Design (RPD) chamber confirmed that the minimum solid angle for four beams is about 5 degrees, a limit set by the steering and focusing magnet geometry outside the containment structure. The SPRFD calls for beam access is through two sets of four ports on opposite sides of the center of the chamber. The RFP design uses liquid jets of FLiBe to control the neutron flux from the igniting pellet. Our initial neutron control will be the natural lithium sabot that carries the fuel pellet into the chamber. This sabot has a 30 cm radius and has two holes that allow access for the four beams from each side. . The entire sabot and a substantial fraction of the lithium rain, and falling liquid sheets surrounding the sabot, will be vaporized as a result of ignition. We estimate that a minimum of 3.5 tons of lithium will be heated to more than 900 degrees during each ignition. Cool <250oC lithium will be sprayed on the walls to create a liquid vortex coated wall to protect the central part of the chamber. Between this continuously coated wall and the hot plasma core will be many jets and sprays of liquid lithium, probably augmented by some cascading sheets of liquid. These liquid sheets, jets, and droplet spray will be the primary blast dampers as well as being the major heat exchange media. The vapor pressure of liquid 250oC lithium will bring the vacuum to 10-5 Torr in less than half a second leaving time to introduce the next pellet and sabot in time for the next shot. Each sabot assembly will be launched from a spinning holder about 12 meters above the chamber center and will be falling about 15 meters a second at the time of ignition. Although direct extraction of energy from the plasma resulting from ignition would be desirable, this is not a process that is currently in practice. Thus our energy extraction will be via heat exchangers to a secondary working fluid thence to thermochemical processes and then steam to drive conventional turbines. The extraction of helium and all three isotopes of Hydrogen, will be a major effort at all times. The secondary working fluid will also have to be treated to prevent Tritium from being transferred to the steam generation system.

Speaker: Charles Helsley (Fusion Power Corporation)

14:35 Study on pulsed-discharge devices with high current rising rate for point spot short-wavelength source in dense plasma observations

Fumitaka Tachinami, Nobuyuki Anzai, Toru Sasaki, Takashi Kikuchi, Nob. Harada Nagaoka University of Technology Kamitomioka 1603-1, Nagaoka, Niigata, 940-2188, Japan An intense short-wavelength light source generated by a pulsed-power device is an important tool for observing interior of dense plasma, lithography, and so on. For observing interior of dense plasmas by scattering and transmission measurement, we required an intense and point-spot like X-ray source, because of the plasmas characteristics is in dense (10-3ρs-ρs, ρs: solid density), small-size (μm-mm), short-lifetime (several 10ns) and optically thin in X-ray region (>6keV). For this reason, we considered the X-ray point-spot light source generated by X-pinch technique. For this application, a pulse power device with high current rising rate should be developed. The parameters required by the equipment for X-pinch are large current (100kA~), short rise time (~100ns) and high current rising rate of 1012-1013A/s [1-3]. For the development of the light source for observation of the dense plasma, we considered an X-pinch light source based on a pulse forming network (PFN) [4]. At the previous study [5], for the optimum and configurable circuit topology, it was found that the 3 LC-ladder PFN was suitable for the X-pinch light source, and the current rising rate of 1012A/s was obtained by circuit simulation. In addition, we constructed the paralleled 3 LC-ladder PFN, and measured the discharge current waveform. As the experimental result, the current rising rate of 3.4x1011A/s was obtained at 12 paralleled PFN system. In this study, we considered the configuration for PFN with the circuit simulations, and constructed the pulsed-power device. We obtained experimentally the discharge current of the constructed pulsed-power device, and compared the characteristics for 2-module and 6-module units, where the one module consists of the 3 LC-ladder PFN. Furthermore, we consider the experimental configuration of X-pinch light source based on the paralleled unit of PFN modules. This work was partly supported by Grant-in-Aid for Challenging Exploratory Research from Japan Society for the Promotion of Science (24656184) and the Union Tool scholarship foundation. [1] J. Wu, et. al., Phys. Plasmas 18, 052702 (2011) [2] A.V. Kharlov, et. al., Rev. Sci. Instrum 77, 123501, (2006) [3] T.A. Shelkovenko, et. al., IEEE Trans. Plasma Sci. 34, 2336 (2006) [4] L.S. Caballero, et. al., IEEE Trans. Plasma Sci. 37, 1948 (2009) [5] T. Miyamoto, et. al., The Seventh Conference on Inertial Fusion Sciences and Applications (IFSA2011), P.We_107 (2011)

Speaker: Fumitaka Tachinami (Nagaoka university of Technology)

14:35 Study on the Dynamics during Longitudinal Compression of Intense Charged Particle Beams with Compact Simulator

Y. Sakai, A. Nakayama, T. Kikuchi (1), J. Hasegawa, M. Nakajima, and K. Horioka Department of Energy Sciences, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama, 226-8502, Japan (1) Department of Electrical Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Niigata 940-2188, Japan Heavy ion beams are expected to be potential drivers for high-energy density physics and heavy ion inertial fusion. For the heavy ion inertial fusion, we need to increase the beam power more than TW level by the acceleration and the bunch compression. Processes of longitudinal beam manipulation and bunch compression are essential to increase the beam power particularly at the final stage of the accelerator. However, in the compression stage, space-charge effects may degrade the beam focus-ability seriously. When the beam bunch is modulated quasi-statically, such as the beam bunching in conventional RF accelerator, emittance growth should be suppressed at a minimum level. In contrast, in the stage of final bunching, a dynamical space-charge effect may induce significant emittance growth. Furthermore, the beam coupling in transverse and longitudinal directions by the space charge effect may cause unpredictable emittance growth during the final bunching. So we intend to investigate the space-charge induced dissipation processes using a compact simulator. We have made a compact bunching simulator based on electron beams. The device consists of an electron gun, an induction voltage modulator, and a solenoidal transport line. For applying the modulation voltage, we use an induction modulator composed of five units with induction adder configuration, which can apply arbitrarily waveforms for the bunch compression. In our experiment, the beam bunch is compressed during the drift in the transport line in which the transverse motion is suppressed by the longitudinal field. Then we expect that all of the dissipation processes are reflected in the compression ratios of the beam current. We compare influence factors for the compression ratios and discuss the condition for the evaluation of dynamical space charge and/or collective effects on the bunch compression, based on the experimental results and a simplified particle transport simulation [1]. As the results indicated that the initial beam brightness should be higher than the present level, we are now planning to increase the brightness of beam source with pulsed thermionic emission. We are also planning to investigate the beam compression ratios as a function of the beam parameters and the transport distance. [1] Y. Sakai, A.Nakayama, M.Nakajima, T.Kikuchi and K.Horioka; Physics and Application of Plasmas based on Pulsed Power Technology, NIFS-Proc. (to be published)

Speaker: Y. Sakai (Department of Energy Sciences, Tokyo Institute of Technology)

17:15 → 18:00 Transportation to Chabot Space and Science Center

18:00 → 21:30 Banquet: Chabot Space and Science Center (http://www.chabotspace.org/index.htm)

21:30 → 22:00 Transportation to the Shattuck Hotel

Friday, 17 August

08:15 → 08:30 Daily Logistics

Conveners: John Barnard (LBNL), Peter Seidl (LBNL)

08:30 → 11:15 High energy density physics & Warm dense matter - Chairs: Y. Oguri and R. Davidson - Featured Posters: K.P. Driver, K, Kondo, Y. Miki, F. Tachinami

08:30 Stopping of Heavy Ion Beams in Dense Plasmas of ICF and WDM Concern

C. Deutsch (1) and N. A. Tahir (2) (1) LPGP UParis-Sud, Orsay, France (2) GSI 1 Planckstr., Darmstadt, Germany The present status of intense and heavy ion beams in the multi MeV/a.m.u energy range and interacting with dense plasma targets at solid density with a few eV temperature is respectively timely reviewed from the heavy ion driven ICF and warm dense matter (WDM) perspectives. Experimental results obtained within SPQR (Stopping Plasma Quantitatively Reinforced)-like setups are consistently analyzed through the Standard Stopping Model (SSM) with emphasis on the dynamics of the projectile effective charge correlated to basic stopping mechanisms[I]. They are shown scalable to ICF requirements including reactor chamber transport and target heating. Further SSM theoretical refinements are also seen mandatory for the WDM experiments planned at Berkeley for low velocity projectiles fully stopped in Bragg peak vicinity, and at GSI for GeV HIB losing only a few percent of their energy in cylindrical (Laplas and Hihex) targets. Potentialities for ion production and acceleration afforded by present and planned (mostly IZEST like) PW-lasers are critically contrasted to standard linear and circular accelerating facilities of fiducial use. [I] C. Deutsch, G. Maynard,M. Chabot,D. Gardes, S. Della Negra, R. Bimbot, M. F. Rivet, C. Fleurier, C. Couillaud, D. H. H. Hoffmann, H. Wahl, K. Weyrich, O. N. Rosmej, N. A. Tahir, J. Jacoby, M. Ogawa, Y.Oguri, J. Hasegawa, B. Sharkov, A. Golubev, A. Fertman, V. E. Fortov and V. Mintsev, The Open Plasma Physics Journal, 3, 88-115 (2010)

Speaker: Claude Deutsch (UParis-Sud)

08:55 Ion Beam Focusing with Cone Optics for WDM Experiments

J. Hasegawa (1); K. Kondo, Y. Oguri (2); and K. Horioka (1) (1) Department of Energy Sciences, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502, Japan (2) Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan Ion beam focusing using cone optics has recently been examined experimentally [1] and numerically [2] and its applicability to accelerator-driven warm dense matter (WDM) experiments is one of the issues to be discussed. This beam-focusing scheme is based on small angle scattering of incident ions by the solid wall of a conical tube. Since the ion scattering depends strongly on various physical quantities such as the scattering angle, the incident ion species and energy, and the atomic composition of the tube wall, systematic investigation over a wide range of these parameters is necessary to understand beam transport physics in the cone optics. The aim of this study is to systematically examine the ion transport through the cone optics by numerical simulations and clarify the potential of this focusing method in the beam parameter ranges relevant to the WDM experiments. The numerical investigation in this study used a three-dimensional Monte Carlo code, which takes into account only elastic scattering between incident ions and target atoms as a stochastic process. The energy loss of the incident ions in the tube wall was calculated using SRIM stopping power data. The beam focusing efficiency was evaluated for various combinations of beam parameter and conical tube material and shape. We found that the use of cones with parabolic wall shapes drastically improves the focusing efficiency although it degrades the output beam quality. The simulation results also showed that the heavier wall material leads to higher focusing efficiency. However, its dependency on the atomic number of the wall material was much weaker than expected from the scattering cross section, indicating that the ion stopping process inside the wall might dominate the overall focusing efficiency of the cone optics. From the results of the systematic investigation, the cone optics designs were optimized for the beam parameters that will be achieved in the future WDM experiments. [1] F.M. Bieniosek, et al., Laser and Particle Beams 28, 209-214 (2010). [2] J. Hasegawa, et al., Journal of Applied Physics, 110, 044913-044919 (2011).

Speaker: J. Hasegawa (1Department of Energy Sciences, Tokyo Institute of Technology)

09:20 X-pinch Diagnostic for Warm Dense Matter and Pulsed-power Developments in Nagaoka University of Technology

Toru Sasaki, Yasutoshi Miki, Fumitaka Tachinami, Hirotaka Saito, Takuya Takahashi, Nobuyuki Anzai, Takashi Kikuchi, and Nob. Harada Nagaoka University of Technology Kamitomioka 1603-1, Nagaoka, Niigata, 940-2188, Japan Warm dense matter (WDM) is of key interest to understand the fusion developments such as an efficient target structure for inertial fusion and/or the first wall of magnetic fusion. Coupled ions, degenerated electrons and the liquid-vapor phase transition should affect the transport properties and the EOS in WDM state. Evaluating properties in WDM state, we have studied pulsed-power systems for the isochoric heating of foamed metal [1-3] and the intense X-ray system [4]. Features of the isochoric heating of foamed metal [1-3] are possible to produce isochoric condition, use of conventional tamper, avoiding skin effect, and direct spectroscopic measurement. The density of WDM can be controlled by enclosed volume of foamed materials. The discharge systems consist on low inductance gap switch and capacitors (3×1.87 μF) charged up to 15 kV. Observed electrical conductivity and foam/plasma temperature is about 104 S/m and 4000 K in 0.1ρs. The observed electrical conductivity is in agreement with the other experimental results and predictions. The temperature dependence of electrical conductivity is neither metallic nor ideal plasma characteristics. For the development of the X-ray light source for observation of the dense plasma, we considered an X-pinch light source based on a pulse forming network (PFN) [4]. The current rising rate of X-pinch light source is estimated to be 1012-1013A/s. For the reducing charged voltages and configurable circuit topology, it was found that the modules of 3-stage LC-ladder PFN were suitable for the X-pinch light source, and the current rising rate of 1012A/s was obtained by the circuit simulation. The discharge current waveform of 3-stage LC-ladder PFN was measured. As the experimental result, the current rising rate of 3.4x1011A/s was obtained at 12 paralleled modules of 3-stage LC-ladder PFN. We consider the experimental configuration of X-pinch light source based on the paralleled unit of PFN modules. This work was partly supported by Grant-in-Aid for Challenging Exploratory Research (24656184) and Grant-in-Aid for Young Scientists (B) (23740406) from Japan Society for the Promotion of Science. [1] Y. Amano, et. al., Submitted to Rev. Sci. Instrum. [2] Y. Amano, et. al., The Seventh Conference on Inertial Fusion Sciences and Applications (IFSA 2011), P.We_85, p.260 (2011). [3] T. Sasaki, et. al., Submitted to IEEE Plasma Sciences. [4] T. Miyamoto, et. al., The Seventh Conference on Inertial Fusion Sciences and Applications (IFSA2011), P.We_107 (2011).

Speaker: Toru Sasaki (Nagaoka University of Technology)

09:45 Discussion

10:00 Plasma physics at the Z6 station, GSI

A. Ortner (1,2); S. Bedacht, S. Busold 2, W. Cayzac, O. Deppert (2); S. Faik (3); A. Frank (1); A. Knetsch, D. Kraus, T. Rienecker (2); D. Schuhmacher (1); F. Wagner (2); M.M. Basko (3,4); V. Bagnoud (2); A. Blazevic (1); G. Schaumann, M. Roth (2). (1) Institut für Kernphysik, Technische Universität Darmstadt, Germany (2) GSI-Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany (3) Universität Frankfurt, Germany (4) ITEP Moscow, Russia The Z6 station at GSI Helmholtzzentrum für Schwerionenforschung offers the unique possibility to conduct combined experiments with two high energy laser systems (nhelix and PHELIX) and a heavy ion beam from the UNILAC accelerator. The PHELIX laser can be operated in a long or short pulse option, the nhelix system deliver up to 3 beams simultaneously on the target and the UNILAC accelerator allows probing with heavy ions ranging from 3 < Z < 92 with energies of 3 – 13 MeV/u. In this talk we will report about the three major experiments at the Z6 station: 1) Energy loss measurements of swift heavy ions in dense carbon plasma heated by hohlraum generated x-rays. A special double hohlraum configuration has been designed to heat carbon homogeneously and to prevent inflow of hot gold plasma into the carbon plasma as well as into the interaction area of the ion beam. Carbon plasmas with an electron density of 1022 cm-3 and an ionization degree of 4 have been generated. The radiation temperatures in the primary and the secondary hohlraum as well as the plasma conditions were characterized and compared with 2D-hydro simulations and theoretical predictions. In the first energy loss experiments with a Ca17+ ion beam with 4 MeV/u we observed an increase of the stopping power of up to 40%. 2) Experimental investigation of the interaction of the ion beam in plasma in the non-linear regime. A hot fully ionized carbon plasma (electron density up to 1021 cm-3 ,electron temperature of 200 eV) is generated by irradiating a thin foil from both sides simultaneously with the nhelix and PHELIX lasers and probed by carbon ions which are slowed down to 0.5 MeV/u. With this set of parameters the projectile velocity is close to the thermal velocity of the electrons and the known linear response theories, like Bethe-Bloch, are not longer valid for energy loss calculations. Strong deviations from the standard approaches are expected. 3) Focusing and coupling of laser accelerated ion bunches into conventional ion optics and RF technology. Aim of this experimental campaign (LIGHT project) is the exploration of the interface between laser ion acceleration (based on "target normal sheath acceleration") and common accelerator technology. It combines in a unique and highly efficient way the capabilities of PHELIX laser (100 TW) with the accelerator know-how available at GSI.

Speaker: Alex Ortner (GSI Darmstadt)

10:25 EOS for WDM

I.V. Lomonosov Institute of Problems of Chemical Physics RAS, Chernogolovka, Moscow reg., 142432, RUSSIA Physical processes arising under conditions of extreme energy densities, such as hypervelocity impacts, action of powerful energy fluxes on condensed matter and others, are typical domains of Warm Dense Matter. They are of interest for fundamental investigations and for numerous practical applications. The typical features of these phenomena are complicated character of 3D gas dynamic flow and big gradients of flow parameters. The numerical modeling of processes at extreme conditions supports experimental investigations in this area. On the other hand, it is the only tool for investigating phenomena which can not been carried out at laboratory conditions. The dramatic progress in the computer industry in past 20 years resulted to the development of high-performance computers and efficient numerical schemes as well. The equation of state (EOS) governing the system of gas dynamic equations defines significantly accuracy and reliability of results of numerical modeling. In our report, we will discuss EOS problems for WDM and will formulate main mathematical and physical demands to wide-range EOS for physical applications. Nowadays, in spite of a significant progress achieved on construction of EOS in solid, liquid and plasma state with the use of the most sophisticated “first-principle” theoretical approaches (classic and quantum methods of self-consisted field, diagram technique, computer’s Monte-Carlo and molecular dynamics methods) the disadvantage of these theories is their regional character. The range of an applicability of each theory is local and, rigorously speaking, no one of them allows to provide for a correct theoretical calculation of thermodynamic properties of matter on the whole phase plane from the cold crystal to liquid and hot plasmas. The principal problem here is the necessity to take into account correctly the strong collective interparticle interaction in disordered media, which meets especial difficulties in the region occupied by dense disordered non-ideal plasmas. In this case experimental data at high pressures, high temperatures are of peculiar significance, because they serve as reference points for theories and semi-empirical models. Data obtained with the use of dynamic methods are of the importance from the practical point of view. Shock-wave methods allow to study a broad range of the phase diagram from compressed hot condensed phase to dense strongly coupled plasma and quasi-gas states. Available experimental data on the shock compression of solid and porous metals as well as isentropic expansion embrace to nine orders with respect to pressure and four to density. Other important information in WDM domain, like measurements of isothermal compressibility in diamond anvil cells, data on sound velocity and density in liquid metals at atmospheric pressure, IEX measurements, possibilities of powerful ion beams, calculations by Debay-Hukkel, Thomas-Fermi models and QMD, evaluations of the critical point are also discussed.

Speaker: I. V. Lomonosov (Institute of Problems of Chemical Physics RAS)

10:50 Intense Ion Beams for Fusion Research

Markus Roth Los Alamos National Laboratory, Technische Universität Darmstadt Ion beams at highest intensities can be provided using either accelerator facilities of high energy short pulse lasers. The synergy of using these two different techniques can lead to a better understanding of the physics of intense beams, the interaction with matter and the production of useful secondary radiation to explore fusion relevant phenomena. The interplay of self generated electric fields with their magnetic counterpart can be studied using small scale laser experiments that lead to first results on new fusion concepts like the X-targets. Moreover short, pulsed, intense ion beams also can serve as a source for secondary radiation that might explore especially the realm of Warm Dense Matter (WDM), a crucial transient state in all fusion experiments. We have explored the use of intense, laser driven ion beams as a compact neutron source for fast neutron radiography in a collaborative effort between LANL, SNL and the TU Darmstadt. First results on recent experiments will be presented as well as a first target design and experiment for a first X-target study.

Speaker: Markus Roth (TUD / LANL)

11:15 → 13:00 Summary and closing remarks