High-Resolution Charged-Particle Spectroscopy with High-Purity Germanium Detectors in the Intermediate Energy Range

Planar detectors to be used for charged particle spectroscopy were prepared from high-purity germanium, p+-contacts being made by boron implantation, n+-contacts by either phosphorus implantation or lithium diffusion. The dead layers of the implanted contacts were about 0.2 μm. Resolution figures for alphas of 155 MeV, scattered under θLAB = 15°, are given and discussed for a diode of 9 mm depletion depth, and for a stack of two diodes each of them having a thickness of 3 mm. The values (comprising the contributions from beam, target, kinematics and electronics) range between 43 keV (fwhm) and 60 keV (fwhm) corresponding to ΔE/E figures between 2.7 and 3.9 × 10-4.