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To account for the dark matter content in our Universe, post-inflationary scenarios predict for the QCD axion a mass in the range $(10-10^3),mumbox{eV}$. Searches with haloscope experiments in this mass range require the monitoring of resonant cavity modes with frequency above 5,GHz, where several experimental limitations occur due to linear amplifiers, small volumes, and low quality factors of Cu resonant cavities. In this paper we deal with the last issue, presenting the result of a search for galactic axions using a haloscope based on a $36,mbox{cm}^3$ NbTi superconducting cavity. The cavity worked at $T=4,mbox{K}$ in a 2,T magnetic field and exhibited a quality factor $Q_0= 4.5times10^5$ for the TM010 mode at 9,GHz. With such values of $Q$ the axion signal is significantly increased with respect to copper cavity haloscopes. Operating this setup we set the limit $g_{agammagamma}<1.03times10^{-12},mbox{GeV}^{-1}$ on the axion photon coupling for a mass of about 37,$mu$eV. A comprehensive study of the NbTi cavity at different magnetic fields, temperatures, and frequencies is also presented.
The axion is a light pseudoscalar particle which suppresses CP-violating effects in strong interactions and also happens to be an excellent dark matter candidate. Axions constituting the dark matter halo of our galaxy may be detected by their resonan
The current status of the QUAX R&D program is presented. QUAX is a feasibility study for a detection of axion as dark matter based on the coupling to the electrons. The relevant signal is a magnetization change of a magnetic material placed inside a
Axions in the micro eV mass range are a plausible cold dark matter candidate and may be detected by their conversion into microwave photons in a resonant cavity immersed in a static magnetic field. The first result from such an axion search using a s
We demonstrate a superconducting (SC) microwave (mw) cavity that can accelerate the dark matter search by maintaining superconductivity in a high DC magnetic field. We used high-temperature superconductor (HTSC) yttrium barium copper oxide (YBCO) wit
Superconducting radio-frequency cavities are commonly used in modern particle accelerators for applied and fundamental research. Such cavities are typically made of high-purity, bulk Nb and are cooled by a liquid helium bath at a temperature of ~2 K.