Characteristics of commercially available CdZnTe detector as gamma-ray spectrometer under severe nuclear accident

Tanimura, Yoshihiko   ; Nishino, Sho   ; Yoshitomi, Hiroshi   ; Kowatari, Munehiko; Oishi, Tetsuya 

At the severe nuclear accidents like the Fukushima Daiichi Nuclear Power Plant, various radionuclides will be dispersed into the environment and raise the dose rate. The - measurements of ray spectra and identifying radionuclides using the results are important for the radiological protection from both external and internal exposure. For this application a commercially available CdZnTe spectrometer (Kromek GR-1) was characterized at the calibration fields of FRS/JAEA. The angular dependence of the detection efficiency was studied and the efficiency was kept within 15 % degradation in 135 degree incident angle, which covers 85 % of all. The usable dose range was evaluated and the spectrometer could correctly measure the ray spectra below 200 Gy/h.