Gamma-ray detection with a large silicon detector in the MeV range

The measurement of gamma rays in the 0.3–30 MeV energy range with silicon detectors at room temperature via Compton scattering is being investigated for the next spatial gamma-ray observatory in the MeV band. In this contribution, we show that 60-keV gamma-ray detection with an energy resolution below 10 keV is possible using a 64×64 mm2, 1.5-mm thick, double-sided stripped silicon detector with a charge-sensitive preamplifier made of discrete commercial components. Our study of the noise including the bias circuit and the connection between the detector and the electronics allowed us to design a system able to sustain a leakage current of ∼50 nA/strip and a capacitance of ∼20 pF/strip. These results encourage us to investigate the use of integrated electronics in view of a satellite mission.