LEGe detector intrinsic efficiency calibration for parallel incident photons

A low energy germanium (LEGe) detector was calibrated by Monte Carlo simulation and experiment with radionuclides. At first, Monte Carlo simulations were carried out for calibrating the detector for parallel incident photons in the 1.5–180 keV energy range. Then, a set of radionuclides emitting low-energy X- or γ-rays was used to calibrate the detector for quasi-parallel incident photons, which provided experimental values to compare with the simulated ones. The results show good agreement with a largest relative discrepancy of −1.8%.