Calculation of Energy Deposition Spectra for Radioactivity Induced in Germanium Gamma-Ray Spectrometers by Various Space Environments

Radioactivity induced in detector materials by cosmic rays and radiation belt protons provides an ultimate limit to the sensitivity of gamma-ray spectrometers used for gamma-ray astronomy and remote sensing spectroscopy of planetary bodies. The increasing use of high resolution germanium spectrometers has made it worthwhile to adapt predictive techniques for this component based on those previously used for alkali halide scintillators. Decay rates of the most significant radionuclides have been calculated using semiempirical cross-sections and combined with Monte Carlo calculations of energy depositions to yield background spectra for both interplanetary space and low earth orbit locations.