Design considerations for trapezoid-shaped Frisch-grid semiconductor radiation detectors

Measurements with 60 keV gamma-rays from a 241Am check source show that most of the volume of a trapezoidal Frisch grid device is active and operates as a detector. Measurements were performed on a trapezoidal device constructed from 'counter grade' CdZnTe material, which despite the lower quality of the starting material still demonstrated excellent energy resolution at relatively high gamma ray energies. The energy resolution was comprised at low energies, most likely due to surface effects and material non-uniformities. Models indicate that performance can be improved with very straightforward and simple design changes.