Off-center efficiency of HPGe detectors

The gamma ray detection efficiency of two HPGe detectors for off-center points was measured both on the detectorʹs cap and outside the detectorʹs cap. It was found that similar to measurements on the detector symmetry axis, for off-center measurements including those outside the detector cap also, the detector could be treated as an effective point detector. The virtual point detector was found to be almost at the same position for vertical and horizontal source displacements.