XEMIS: Liquid Xenon Compton Camera for 3γ Imaging

International audience; An innovative liquid xenon Compton camera project, XEMIS (XEnon Medical Imaging System) has been proposed by SUBATECH laboratory, for a new functional medical 3γ imaging technique based on the detection in coincidence of 3 γ-rays. The purpose of this 3γ imaging modality is to obtain a 3D image using 100 times less activity than in current PET systems. The combination of a liquid xenon time projection chamber (LXe TPC) and a specific (β$^{+}$, γ) radionuclide emitter$^{44}$Sc is investigated in this concept. In order to provide an experimental demonstration for the use of a LXe Compton camera for 3γ imaging, a succession of R&D programs, XEMIS1 and XEMIS2, have been carried out using innovative technologies. The first prototype XEMIS1 has been successfully validated showing very promising results for energy, spatial and angular resolutions with an ultra-low noise front-end electronics. The second phase dedicated to a 3D imaging of small animals, XEMIS2, is now under installation and qualification, while the characterizations of ionization signal using Monte Carlo simulation has shown preliminary good performances for energy measurement.