PNNL

Abstract

Microwave cavities have been deployed to search for bosonic dark matter candidates with masses of a few µeV. However, the sensitivity of these cavity detectors is limited by their volume, and the traditionally employed half-wavelength cavities suffer from a significant volume reduction at higher masses. ADMX-Orpheus mitigates this issue by operating a tunable, dielectrically-loaded cavity at a higher-order mode, which allows the detection volume to remain large. The ADMXOrpheus inaugural run excludes dark photon dark matter with kinetic mixing angle ? > 10-13 between 65.5µeV (15.8GHz) and 69.3µeV (16.8GHz), marking the first tunable microwave cavity dark matter search beyond 7.3GHz.