Test of a Compton telescope prototype based on continuous LaBr3 crystals and silicon photomultipliers

A Compton telescope prototype for dose monitoring in hadron therapy is under development. It will consist of three detector layers and each layer will be made of a continuous LaBr₃ crystal coupled to four Silicon Photomultiplier (SiPM) arrays. As a first test, a small prototype made of only two detectors layers has been assembled. The camera is based on continuous LaBr₃ and LYSO crystals coupled to a SiPM arrays for gamma-ray detection and readout. The setup consists of a 16×18×5 mm³ LaBr₃ crystal coupled to a SiPM array as the first layer of the telescope, and a 16×18×5 mm³ LYSO crystal coupled to another SiPM array as the second layer. The SPIROCI ASIC is employed in the readout electronics. The first coincidence tests have been successfully carried out, using a ²²Na source placed at different positions, and allow the reconstruction of a point-like source, encouraging the development and the improvement of the prototype to a full imaging system.