First axion dark matter search with toroidal geometry

Abstract

We firstly report an axion haloscope search with toroidal geometry. In this pioneering search, we exclude the axion-photon coupling g aγγ down to about 5×10 −8 GeV −1 over the axion mass range from 24.7 to 29.1 μ eV at a 95\% confidence level. The prospects for axion dark matter searches with larger scale toroidal geometry are also considered. © 2017 American Physical Society