Study on the measurement of gamma-ray radiation field by IPs

The IPs (imaging plate) have excellent characteristics of high radiation sensitivity and good position resolution, however, few data are available on the absolute IP sensitivities to X/γ-ray with mid/high energy. In order to apply them to the reference radiation field measurement, the performance of IPs with ¹³⁷Cs was studied: The two-dimensional distribution of reference radiation field was obtained, the radiation field size and uniformity were measured through the two-dimensional distribution diagram, which is the same with the results obtained by scanning the ionization chamber. Based on the accuracy of the IPs' results, study on the fade rates of IPs was carried out, then the correction coefficient of signal fading was obtained. The absorbed dose response of IPs for gamma-ray was got,and the R² of the linear fitting is 0.99977. Besides, the dependence on dose-rate of the absorbed dose response of IPs was experimented, then the correction coefficient about dose-rate was given in this paper. This work provides the necessary data support and technical basis for the application of the IPs to the reference radiation measurement. (authors)