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 mm
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, 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.