Non-magnetic glass-fiber cryostat for MADMAX prototype tests

Abstract MADMAX, an axion dark matter search experiment, is currently in the prototype testing phase. Its working principle is based on the conversion of axions in a magnetic field into photons. This signal is then enhanced by a booster made of dielectric disks placed in front of a mirror. In order to test MADMAX prototypes at cryogenic temperatures in a magnetic field parallel to the disks, a new G-10 glass-fiber cryostat of 0.06,m 3 inner volume was designed, tested and used in a CERN magnet. The design allows to minimise cost as well as cooling down and warming up times. Using continuous circulation flow of gaseous helium, the MADMAX prototype was cooled down reproducibly to temperatures below 10 K for more than 24 hours. This procedure allowed, for the first time, to perform a calibration of the booster response and to run a dark matter axion search in a magnetic field at low temperatures. This novel type of cryostat, with a low manufacturing cost, fast and easy to operate, could be used for other purposes beyond MADMAX.