Multi-cavity Resonator Designs for the ADMX-Extended Frequency Range

Axion dark matter is compelling particle that could account for all the dark matter in the Universe and also resolve the Strong CP problem in QCD physics. Axion haloscopes probe for axion dark matter in the Milky Way halo through the coupling of axions to microwave photons in an external magnetic field. Conventional haloscopes utilize a single resonator to enhance the conversion of axions into microwave photons. ADMX-Extended Frequency Range will use a multi-cavity design to search for axions in the range from 2-4 GHz. This talk will provide updates on developments in the resonator design and tuning systems for ADMX-Extended Frequency Range.