Pulse shape simulation for segmented true-coaxial HPGe detectors

Abstract

A new package to simulate the formation of electrical pulses in segmented true-coaxial high purity germanium detectors is presented. The computation of the electric field and weighting potentials inside the detector as well as of the trajectories of the charge carriers is described. In addition, the treatment of bandwidth limitations and noise are discussed. Comparison of simulated to measured pulses, obtained from an 18-fold segmented detector operated inside a cryogenic test facility, are presented.

Production, characterization and operation of $$^{76}$$ 76 Ge enriched BEGe detectors in GERDA

“…15). A few detectors like GD35B, however, fluctuate up to ±30 % translating into a ∼0.1 mm [43] FCCD difference. The count rate profile on the front side area of these detectors is characterized by higher count rates at the center and at the outermost bor- Spatial dependence of the pulse shape response The pulse shapes of events in a ±4.5 σ region around the 60 keV γ -peak were investigated for every scanned point.…”

Sensitivity of GRETINA position resolution to hole mobility

“…Drift velocity anisotropy can cause considerable differences in pulse shape rise time depending on the spatial position of the charge carrier creation. Experimentally, the dependence of pulse shapes on the electron drift velocity 110 anisotropy in closed-end HPGe detectors has been clearly established [14], as well as its influence on tracking algorithms [15]. Anisotropy in the drift velocity for holes is also a major concern when dealing with semi-conducting devices operating at high-115 electric fields, where deviation from low-field ohmic behavior is observed [16].…”

“…The next-generation devices advancing current frontiers 10 of nuclear spectroscopy are eliminating the lowresolution scintillator envelopes entirely and consist of a 4π HPGe shell. The individual crystals have electrically segmented outer contacts which can be used to reconstruct gamma-ray interaction points 15 with σ ∼ 2mm RMS resolution [1], [2]. This position sensitivity is necessary to allow gamma-ray tracking through the HPGe volume, which enables the iden- * Corresponding author.…”

Signal recognition efficiencies of artificial neural-network pulse-shape discrimination in HPGe $$\varvec{0\nu \beta \beta }$$ 0 ν β β -decay searches

“…See e.g. [1,2] for a detailed description of the pulse creation process. For photons in the MeV range, the dominant interaction process is Compton scattering.…”