Performance of CdZnTe geometrically weighted semiconductor Frisch grid radiation detectors

Semiconductor Frisch grid radiation detectors have been manufactured and tested with encouraging results. Resolution enhancement occurs as a result of combining the geometric weighting effect, the "small pixel" effect and the Frisch grid effect. The devices are operated at ambient temperature without any pulse shape correction, rejection and compensation techniques. The new devices are manufactured from CdZnTe and do not require any cooling for operation. The geometrically weighted detectors have only one signal output to a standard commercially available Ortec 142A preamplifier. The detectors operate with simple commercially available NIM electronics, hence the device design can be coupled to any typical NIM system without the need for special electronic instruments or circuits. Geometrically weighted detectors that are 1 cubic centimeter in volume were fabricated from "counter grade" material, yet have shown room temperature energy resolution of 7.5% FWHM (at 29 degrees C) for Co-57 122 keV gamma rays and 2.68% FWHM (at 23 degrees C) for Cs-137 662 keV gamma rays.