Feasibility study on determining the conventional true value of gamma-ray air kerma in a minitype re

• 作 者: Yi-Xin Liu Biao Wei Yang Xu Meng He Ren-Hong Zhuo De-Zhi Wen Da-Jie Ding Ben-Jiang Mao
• 机 构: Key Laboratory of Optoelectronics Technology and System,Ministry of Education,Chongqing University,I
• 出 处: Nuclear Science and Techniques
• 发表日期: 2017年06期
• 关键词: gamma kerma dimensions scattered spectrometer calibration negligible determining

A minitype reference radiation(MRR) with dimensions of only 1 m × 1 m × 1 m has been developed for the in situ calibration of photon dosimeters.The present work conducts a feasibility study on determining the conventional true value of gamma-ray air kerma at the point of test in the MRR.Owing to its smaller dimensions,the scattered gamma-rays in the MRR are expected to induce a non-negligible interference with the radiation field compared with conditions in the standard reference radiation stipulated by ISO4037-1 or GB/T12162.1.A gamma-ray spectrometer was employed to obtain the spectra of scattered gamma-rays within the MRR,and the feature components of the spectra were extracted by principal component analysis to characterize the interference of a dosimeter probe in the radiation field.A prediction model of the CAK at the point of test was built by least squares support vector machine based on the feature component data obtained from nine sample dosimeters under five different dose rates.The mean prediction error of the CAK prediction model was within ±4.5%,and the maximum prediction error was about ±10%.

A minitype reference radiation (MRR) with dimensions of only 1 m × 1 m × 1 m has been developed for the in situ calibration of photon dosimeters. The present work conducts a feasibility study on determining the conventional true value of gamma-ray air kerma at the point of test in the MRR. Orwing to its smaller dimensions, the scattered gamma-rays in the gammaRray is the non-negligible interference with the radiation field compared with conditions in the standard reference radiation stipulated by ISO 4037-1 or GB / T12162.1.A gamma-ray spectrometer was employed to obtain the spectra of scattered gamma-rays within the MRR, and the feature components of the spectra were extracted by principal component analysis to characterize the interference of a dosimeter probe in the radiation A prediction model of the CAK at the point of test was built by least squares support vector machine based on the feature component data obtained from nine sample dosimeters under five different doses the mean prediction error of the CAK prediction model was within ± 4.5%, and the maximum prediction error was ± ± 10%.