Gamma-ray tracking with segmented HPGe detectors

Abstract

This paper gives a brief overview of the technical progress that can be achieved with the newly available segmented HPGe detectors. Gamma-ray tracking detectors are a new generation of HPGe detectors which are currently being developed to improve significantly the efficiency and resolving power of the 4π germanium detectors arrays for high-precision γ-ray spectroscopy. They consist of highly segmented HPGe detectors associated with fast digital front-end electronics. Through the pulse-shape analysis of the signals it is possible to extract the energy, timing and spatial information on the few interactions a γ-ray undergoes in the HPGe detector. The tracks of the γ-rays in the HPGe detector can then be reconstructed in three dimensions based on the Compton scattering formula. Such a detector has been used for the first time during an in-beam experiment. The γ-decay of the Coulomb excitation of a 56 Fe nucleus was measured with the highly segmented MARS prototype positioned at 135 degree. The energy resolution has been improved by a factor of 3 as compared to standard HPGe detectors due to very precise Doppler correction based on knowledge of the γ-ray track.

A fast VLSI preamplifier for segmented HPGe γ-ray detectors

“…The availability of highly segmented HPGe detectors, makes it possible to measure the spatial coordinates of the points where the impinging gamma photon interacts inside the detector crystal, and to perform the so-called gamma-ray tracking [1][2][3]. Segmented HPGe detectors will be employed worldwide in the near future for next-generation nuclearphysics experiments with exotic ion beams.…”