First QUAX galactic axions search with a SC resonant cavity

Quax is an axion haloscope that can search for axions by means of either their coupling with electron spins or with photons, making use of superconducting resonant cavities. A superconducting NbTi cavity was characterized at T = 4 K in a magnetic field. The cavity exhibited a quality factor of Q0 = 4.5 × 105 for the TM010 mode at 9 GHz in a 2 T magnetic field. Since the results were satisfactory, this cavity was also operated in a set-up to measure the axion coupling with photons, gaγγ. This resulted in an upper limit of gaγγ < 1.03 × 10−14 GeV−1 for an axion mass of about 37 μ eV.