First tests and MonteCarlo simulations of a compton camera with Si-pad detectors and highly-segmented HPGe detectors

The impetuous progress of the detection systems in nuclear medicine are based on major improvements of the sensitivity of the new detector systems and on the highly-integrated low-noise associated electronics, offering valuable solutions for the diagnostic of premature biological lesions. Most of the presently available detectors for nuclear medicine employ mechanical collimation, which couples the detection sensitivity to the spatial resolution. The electronic collimation of Compton cameras can overcome this drawback, but drastically reduces the efficiency due to the coincidence measurement. However, the Compton imaging systems can offer advantages over the traditional ones and the study of innovative solutions involving the newest available detectors and electronics could lead to unexpectedly good results. Our goal is to design a Compton camera based on Si-pad detectors and ASIC electronics. We performed extensive Monte Carlo simulations for systems consisting of Si-pad detectors with various thickness and pad dimensions, as well as for different geometries. The various Si-pad detectors were characterized before the bonding to the ASIC electronics and the whole assembly was subsequently tested with a VA-DAQ acquisition system from IDEAS. The results of the characterization measurements and tests will be presented