Gamma-Ray Response of a 38-mm Bismuth Germanate Scintillator

The response of a 38-mm-diam by 38-mm-long bismuth germanate (BGO) scintillator to gamma radiation from 0.12 to 8.28 MeV has been measured. The full-energypeak efficiency of the detector, which varies from 80% at 0.12 MeV to 10.8% at 8.29 MeV, is 5.6 times as great at 2.75 MeV as the full-energy efficiency of a similar NaI (Tl) detector. Although the energy resolution of the detector is inferior to that which may be obtained with NaI (Tl), its high peak-to-Compton ratio and high full-energy-to-escape-peak ratio is advantageous. This detector shows promise of application in many fields.