Silicon photo-multiplier readouts for scintillators in high-energy astronomy

New scintillator materials have recently been shown to hold great potential for low-cost, reliable gamma-ray detectors in high-energy astronomy. New devices for the detection of scintillation light promise to make scintillator-based instruments even more attractive by reducing mass and power requirements. In particular, silicon photo-multipliers (SiPMs) are starting to become commercially available that offer gains and quantum efficiencies similar to those of photo-multiplier tubes (PMTs), but with greatly reduced mass, high ruggedness, low voltage requirements, and no sensitivity to magnetic fields. We have conducted laboratory tests of a sample of commercially available SiPMs coupled to LaBr3:Ce, a scintillator of relevance to future high-energy astrophysics missions. We present results for gamma-ray spectroscopy, compare the SiPM performance to that of a PMT, and discuss the extent to which SiPMs offer significant advantages for scintillator-based space missions.