Status of DMRadio-50L and DMRadio-m$^3$

Abstract

Recent theoretical advancements have made the QCD axion a stronger dark matter candidate, especially in the sub-$\mu\text{eV}$ range. While cavity haloscopes have made significant progress in excluding QCD axions in the $1 - 100\ \mu\text{eV}$ region, the $1 \text{ peV} - 1\ \mu\text{eV}$ region remains unexplored. The DMRadio program consists of a series of experiments designed to probe low mass axions. DMRadio-50L uses a 1 T average field toroidal magnet and a high-Q LC-oscillator with target sensitivity to axions of $g_{a\gamma\gamma} <5\times10^{-15}\text{ GeV}^{-1}$ between 5 kHz and 5 MHz. DMRadio-m$^3$ consists of a higher frequency LC-oscillator in a 4 T peak field solenoidal magnet with sensitivity to the DFSZ model of QCD axions between 30 MHz and 200 MHz. In this work, we present the status of DMRadio-50L and DMRadio-m$^3$.