Completion of Phase I and Preparation for Phase II of the HAYSTAC Experiment

Abstract

The HAYSTAC experiment utilizes a tunable resonant microwave cavity to search for dark matter axions. We report on the system and the results from Phase I of the experiment. This phase relied on a 9 T magnet, Josephson parametric amplifiers, and a dilution refrigerator for the operation of the experiment. Axion models with two photon coupling $g_{a\gamma \gamma }\gtrsim 2\times 10^{-14}\mathrm{GeV}$ were excluded in the $23.15<m_a<24.0\mu \mathrm{eV}$ mass range. Phase II of the experiment will include upgrades to the cryogenics system and a new squeezed-state receiver. Finally, we discuss work on multi-rod cavities and photonic band gap resonators for higher frequency operation.

5 pages, 3 figures. Contributed to the 14th Patras Workshop on Axions, WIMPs and WISPs, DESY in Hamburg, June 18 to 22, 2018