Measurement of air kerma rate and ambient dose equivalent rate using the G(E) function with hemispherical CdZnTe detector

Abstract

Since the room-temperature detector CdZnTe (CZT) has advantages in terms of detection efficiency, energy resolution, and size, it has been extensively used to detect X-rays and gamma-rays. So far, nuclear radiation detectors such as cerium chloride doped with lanthanum bromide (LaBr $$_3$$ (Ce)), thallium doped with cesium iodide (CsI (Tl)), thallium doped with sodium iodide (NaI (Tl)), and high-purity germanium (HPGe) primarily use the spectroscopy-dose rate function (G(E)) to achieve the accurate measurement of air kerma rate ( $$\dot{K}_{a}$$ ) and ambient dose equivalent rate ( $$\dot{H}^*(10)$$ ). However, the spectroscopy-dose rate function has been rarely measured for a CZT detector. In this study, we performed spectrum measurement using a hemispherical CZT detector in a radiation protection standards laboratory. The spectroscopy-dose rate function G(E) of the CZT detector was calculated using the least-squares method combined with the standard dose rate at the measurement position. The results showed that the hemispherical CZT detector could complete the measurement of air kerma rate ( $$\dot{K}_{a}$$ ) and ambient dose equivalent rate ( $$\dot{H}^*$$ (10)) by using the G(E) function at energies between 48 keV and 1.25 MeV, and the relative intrinsic errors were, respectively, controlled within ± 2. 3 and ± 2. 1%.