Energy response of a novel compact Ge+BGO spectrometer for 4–20 MeV γ-rays

Abstract

The energy response of a novel composite Ge+BGO spectrometer has been measured for high-energy (4–20 MeV) photons. The spectrometer consists of a cooled Ge solid state central detector surrounded by a single BGO scintillator crystal without having interfering materials in between. Good energy resolution (≈1.7%) combined with a considerable photopeak efficiency ( ε≈17%) have been obtained at 15.1 MeV in “adding-back” mode. GEANT Monte-Carlo code simulations reproduce the measured response rather well and show a very good suppression factor against neutrons (≥100) and also against cosmic rays (≥3000) for this composite spectrometer.