The axion haloscope is the currently most sensitive method to probe the vanishingly small coupling of this prominent Dark Matter candidate to photons. To scan a sizeable axion Dark Matter parameter space, the cavities that make up the haloscope need to be tuned efficiently. In this article, we describe a novel technique to tune axion haloscopes around 8.4~GHz in a purely mechanical manner without the use of dielectrics. We achieve tuning by introducing a gap along the cavity geometry. A quality factor reduction of less than 20\% is achieved experimentally for a tuning range of around 600~MHz at room temperature and at cryogenic temperatures for around 300~MHz. A larger tuning range would require an improved alignments mechanism. We present the results of a corresponding prototype and outline prospects to further develop this technique.
@article{arxiv.2312.13109,
title = {Split-cavity tuning of a rectangular axion haloscope operating around 8.4 GHz},
author = {Jessica Golm and Jose María García-Barceló and Sergio Arguedas Cuendis and Sergio Calatroni and Walter Wuensch and Babette Döbrich},
journal= {arXiv preprint arXiv:2312.13109},
year = {2025}
}