Verification of the method of average angular response for dose measurement on different detectors

Abstract

At present most radiation dose meters have serious problems on aspects of energy response and angular response. In order to improve the accuracy of dose measurements, a method of average angular response has been proposed. The method can not only correct the energy response, but also the angular response. This method has been verified on NaI(Tl)(50 mm×50 mm) scintillation detectors, but has not been proved on other types and sizes of detectors, In this paper the method is also verified for LaBr 3 (Ce) scintillation detectors and HPGe detector To apply the method, first of all, five detectors are simulated by Geant4 and average angular response values are calculated. Then experiments are performed to get the count rates of full energy peak by standard point source of 137 Cs, 60 Co and 152 Eu. After that the dose values of five detectors are calculated with the method of average angular response. Finally experimental results are got. These results are divided into two groups to analyze the impact of detectors of various types and sizes. The result of the first group shows that the method is appropriate for different types of detector to measure dose, with deviations of less than 5% compared with theoretical values. Moreover, when the detector's energy resolution is better and the count rate of the full energy peak is calculated more precisely, the measured dose can be obtained more precisely. At the same time, the result of the second group illustrates that the method is also suited for different sizes of detectors, with deviations of less than 8% compared with theoretical values.

Comparison of two spectrum-dose conversion methods based on NaI(Tl) scintillation detectors

“…As shown in figure 3, figure 4, and figure 5, energy spectra of three sources detected by the NaI (Tl) scintillator are similar to those of other experiments [2]. The energy resolution of the detector is 7.9% at 662 keV.…”

“…Therefore, these dosimeters are not convenient, especially in emergency scenarios. Pulse-mode dosimeters base on G-M counters, scintillation detectors and semiconductors have been applied in many different workplaces to monitor radiation doses [2]. G-M counter dosimeters were widely used in recent decades, for they were inexpensive.…”