Earlier developed CdTe p–i–n detectors technology (energy resolution is close to the Ge ones) gives a possibility to solve various tasks of γ-active materials control. For inspection of the materials irradiating γ-quanta with energies of 100–400keV (for example, U, Pu), it is sufficient to increase the sensitive area of detector up to 4–5cm2 (with the thickness about 2.5–3mm). It might allow measurement of the nuclear materials characteristics using standard software, designed for Ge detectors. The research results for large square CdTe p–i–n detectors and detection systems development will be demonstrated in this work. The factors limiting energy resolution and other characteristics (peak-to-background ratio, shape of amplitude distribution, charge losses) of the large CdTe detectors will be discussed.

A breakthrough in the performance of p–i–n CdTe and CdZnTe detectors is reported. The detector stability has been significantly improved, allowing their use in precise gamma and XRF applications. Detectors with energy resolution close to Si and Ge were produced operating with only −30–−35°C cooling (by a Peltier cooler of 15×15×10mm size and a consumed power less than 5W). Presently detectors with volume of up to 300mm3 are available. In terms of photoelectric effect efficiency it corresponds to HPGe detectors with volumes of about 1.5cm3. The possibilities of further improvement of CdTe and CdZnTe detector characteristics are discussed in this paper.