No abstract

One of the main electronic noise sources of a room temperature spectroscopy system is the leakage current of a detector. It can be reduced with a pn-junction type detector structure such as a M-i-n configuration, and with cooling. In this work eight CdZnTe detectors with a M-i-n structure were fabricated by indium diffusion. The junction was characterized by a currentvoltage technique. Detector electrical, charge collection and spectroscopic properties were compared to the ones received with the traditional electroless Au contacts, before the junction formation. As a result of the indium diffusion an improved detector leakage current performance was achieved. However, a corresponding improvement in the detector energy resolution was not always observed due to the CdZnTe charge collection properties and process variables.

Presently room-temperature CdZnTe (CZT) nuclear radiation detectors of various designs and sizes are widely used for spectrometric measurements of X and gamma-radiations. In most cases the spectrometric detectors with highest efficiency are requiredl. But there are tasks where good spectrometric detectors with a low efficiency should be applied. Those are tasks connected with spectrometric measurements in strong radiation fields where small size quasi-hemispherical CZT detectors can be used. Now the quasi-hemispherical CZT detectors with a very small volume of about 0.5 mm3 are available. These detectors have energy resolution (FWHM) from 1% to 2% at a 662 keV.The possibilities and limitations of the miniature detection probes with CZT detectors for application in strong radiation fields are discussed in the report. Some results of these probes application for irradiated nuclear spent fuel and other high-level objects spectra measurements under water in a NPP cooling pond are presented.

No abstract