Thick silicon strip detector Compton imager

We present initial results obtained with double-sided, thick (2 mm) silicon strip detectors used as a Compton imager. A reconstructed image of a gamma ray source and a spectrum of the gamma ray energy are produced at room temperature using the multiple Compton technique. Multiple Compton interactions allow the energy and Compton scattering angle to be reconstructed without having to absorb the energy of the incident gamma ray completely. This extends our work on multiple Compton imagers using germanium strip detectors to silicon detectors that operate at higher temperatures. The detectors are 57 × 57 mm in active area and are 2 mm thick with 64 strips per side with a pitch of 0.9 mm. The energy resolution of the detectors for 60 keV gamma rays are 3-4 keV at room temperature and 2.1 keV at -20°C. Simulations of the imager are performed in GEANT4, including Doppler broadening, and show agreement with the real data.