DARK NOISE CURRENTS AND ENERGY RESOLUTION OF CDZNTE SPECTROMETERS

The effect on energy resolution of dark noise currents experimentally observed ill state of the art CdZnTe spectrometers is quantitatively a nalyzed. Expressions for the energy resolution determined by shot nois e, generation-recombination noise, and 1/f noise are discussed in turn and are compared with the linewidth due to incomplete charge collecti on. The effect of the dark noise upon energy resolution is directly me asured by monitoring the broadening of peaks provided by a pulser, due to biased, non-irradiated CdZnTe spectrometers that are connected in parallel. The noise characteristics of the spectrometers under study w ere measured separately and their dominant noise mechanism is characte rized. In this manner, the effect on resolution of the dark noise is c orrelated not only with the dc value of the dark current but also with the noise spectral behavior which is determined by the noise mechanis m.