Efficiency of segmented HPGe detectors: design criteria for pulse shape analysis

The problems with reconstructing the trajectory of γ-rays and identifying their interaction points in segmented coaxial HPGe detectors are discussed here in view of their importance in the design of the next generation of detector arrays for γ-ray spectroscopy studies. In fact, the tracking quality of the γ-ray interactions in the medium controls the overall detection efficiency. This paper focuses on two main points. One is the study of how the tracking reconstruction efficiency is affected by the ability of disentangling multiple interactions per segment. The other is the study of the consequences that different types of segmentation have on the overall efficiency. Two geometries have been chosen: that of a single cylindrical detector and that of a spherical shell