Geometrically weighted semiconductor Frisch grid radiation spectrometers

A new detector geometry is described with relatively high gamma ray energy resolution at room temperature. The device uses the geometric weighting effect, the small pixel effect and the Frisch grid effect to produce high gamma ray energy resolution. The design is simple and easy to construct. The device performs as a gamma ray spectrometer without the need for pulse shape rejection or correction, and it requires only one signal output to any commercially available charge sensitive preamplifier. The device operates very well with conventional NIM electronic systems. Presently, room temperature (23°C) energy resolutions of 2.68% FWHM at 662 keV and 2.45% FWHM at 1.332 MeV have been measured with a 1 cm3 prism shaped CdZnTe device.