Session Y09: Axion II

Photonic Band Gap resonators for HAYSTAC

Axion haloscopes are detectors used to search for dark matter axions via their conversion to photons. Haloscopes rely in part on the use of tunable electromagnetic resonators to enhance the converted photon signal. Existing haloscopes use traditional microwave cavities that support many fundamental eigenmodes. However, only a limited subset of the cavity modes can be used for data collection. Mode mixing and crowding limit the available tuning range in current cavities and pose challenges for accessing new regions of parameter space. Photonic Band Gap (PBG)-based resonators allow for the confinement of the modes of interest while eliminating unwanted modes. By eliminating mode crossings, PBG resonators can provide larger uninterrupted tuning ranges and avoid mode crowding at higher frequencies. In this talk, we present updates on the ongoing development of tunable PBG resonators for HAYSTAC and results from testing a first prototype design.   

CAPP-8TB axion haloscope for a mass range of 6.62 - 7.03 μeV

CAPP-8TB is a microwave cavity axion search experiment at IBS/CAPP designed to be sensitive to cold dark matter axion within a significant mass range. The coupling signal from axions and virtual photons, is enhanced by a high Q factor cavity of 3.5 L volume placed at a cryogenic temperature around 50 mK. A superconducting magnet provides a stable 8 T static magnetic field, and a low noise HEMT amplifier for the first amplification of the signal guarantees less than 2 K of the effective noise temperature of the receiver chain. As a result, CAPP-8TB’s first phase run is expected to reach four times KSVZ sensitivity within three months for the 6.62 – 7.03 μeV axion mass range. Preliminary results from the first phase run as well as plans for the second phase run with a SQUID amplifier will be shown during the presentation.