New cryogenic processes implemented for 3γ medical imaging with liquid xenon.

Our researches are geared towards a new low activity functional imaging technique named “3γ medical imaging” which requires a liquid xenon Compton camera. A specific detector, XEMIS2, has been developed and optimized for that purpose. The XEMIS2 camera is held in a cryostat connected to a purification circuit and a cryogenic tank called ReStoX. ReStoX is in charge of the xenon boil-off driving, the detector filling with liquid xenon at controlled pressure and temperature (1.2 bara at 168 K), the xenon recovering and storage. Our first studies have validated the ReStoX’s thermal behaviour and its ability to stabilize the pressure. We deduced a total heat losses reaching 17 W, a warm up duration close to 7 months and its clear ability to maintain a constant pressure (around 1 mbar mean fluctuation between peaks). Now we are ready to connect it to the cryostat.