Speaker
Prabir Roy
Description
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.
Primary author
Prabir Roy
