Speaker
Prof.
Karl van Bibber
(University of California Berkeley)
Description
HAYSTAC (Haloscope At Yale Sensitive To Axion CDM) is a microwave cavity experiment designed both as a data pathfinder and innovation test-bed, in the 3–12 GHz (12–50 $\mu$eV) mass range. The Phase I run program (2016–17) covered a small region of mass around 24 $\mu$eV, achieving a sensitivity in axion-photon coupling well into the range of realistic axion models for a standard halo density. With a tunable annular copper cavity of only 1.5 L volume in a 9 T superconducting magnet, HAYSTAC achieved a system noise temperature of only 2× the Standard Quantum Limit ($k_{B}T_{SYS} = h\nu$), an order of magnitude improvement over any other experiment; its extraordinary sensitivity owing to the first-ever use of Josephson Parametric Amplifiers (JPA) and a dilution refrigerator in a microwave cavity experiment. Currently, a 2-JPA squeezed-vacuum state receiver is being integrated into the experiment that will enable a significant speed up of data taking; commissioning will begin early summer. Innovations in microwave resonators will also be described, such as Photonic Band Gap structures to eliminate interference from unwanted TE-modes with the TM010-like mode of interest, which couples to the axion field.
| karl.van.bibber@berkeley.edu | |
| Collaboration name | HAYSTAC |
| Funding source | This work was supported by the National Science Foundation, under grants PHY-1362305 and PHY-1607417, by the Heising-Simons Foundation under grants 2014-181, 2014-182, and 2014-183, and by the U.S. Department of Energy through Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. |
Primary author
Prof.
Karl van Bibber
(University of California Berkeley)
