The VORTEX cavity for the RADES axion haloscope

Abstract

One of the major challenges in axion dark matter haloscope searches is a loss-less tuning mechanism that is able to cover a significant frequency range around the haloscope's central frequency. In this article, we report on the implementation and performance of an axion haloscope dubbed Vertical-cut Optimised Resonant Tunable cavity for dark matter EXploration (VORTEX) centred at $8.5$ GHz with a tuning range of around $800$ MHz. The performance of this setup is measured at temperatures in the mK range and compared to simulation. In addition, we test the cavity-mode structure of this cavity type directly via the `bead-pull method' and observe satisfactory agreement with expectations. The arrangement is poised to be used in an upcoming RADES (Relic Axion Detection Exploratory Setup) data-taking campaign employing a $12$ T solenoid magnet.