The Grenoble Axion Haloscope platform (GrAHal): development plan and first results

Understand

In this note we report on the development plans and first results of the Grenoble Axion Haloscope (GrAHal) project.

• It is aimed at developing a haloscope platform dedicated to the search for axion dark matter particles.
• We discuss its general framework and the plans to reach the sensitivity required to probe well known invisible axion models, over particularly relevant axion masses and coupling regions.
• We also present our first haloscope prototype and the result of its test run at liquid He temperature, setting a new exclusion limit $g_{a \gamma \gamma} \leq 2.2 \times 10^{-13}~ \text{GeV}^{-1}$ ($g_{a \gamma \gamma} \leq 22 \times g_{\text{KSVZ}}$) around 6.375 GHz ($m_a \simeq 26.37$ $\mu \text{eV}$).