The axion, originally introduced as a solution to the Strong CP problem of QCD, is an appealing dark matter candidate due to its weak interactions with the standard model and its cosmological production mechanisms. Experimental searches for dark matter axions use the axion’s coupling to standard model photons. In the presence of a dc magnetic field, the axion produces a narrowband electromagnetic response at a frequency set by its mass. This electromagnetic excess is subsequently enhanced using high-Q tunable resonators. The DMRadio collaboration uses superconducting LC oscillators, large dc magnetic fields, and superconducting sensors operating beyond the standard quantum limit to search for axion masses in the neV mass range, with the ultimate goal of sensitivity to QCD axions at 1 neV. These masses correspond to kHz-MHz frequencies. In this talk, we present the ongoing commissioning status of the DMRadio-50L experiment at Stanford University. This experiment uses a 1 T toroidal magnet and dc SQUIDs to search for dark matter axions. We also present the design of DMRadio-Core. The DMRadio-Core experiment proposes to use a novel configuration of compact solenoidal magnets to search for axions in the 120-800 neV range. This design of DMRadio-Core sheds light on the design of the ultimate DMRadio experiment, DMC-GUT, which searches for axions at the GUT-scale (0.4-120 neV).
