Wu Jinjie

10-50 kV X射线水吸收剂量的测量与研究

X射线水吸收剂量是辐射剂量学的重要物理量，它的精确测量在放射治疗中至关重要。开展低能X射线水吸收剂量的研究与测量，可为完善水吸收剂量溯源体系及扩宽计量部门校准范围提供重要技术支持。确定低能X射线水吸收剂量的测量方法，在辐射场中使用PTW23344电离室对10-50 kV的治疗水平辐射质下的X射线水吸收剂量进行了测量。最终得到了电离室的水吸收剂量刻度因子 N D 以及厚度为6 cm有机玻璃前表面的水吸收剂量 D W 。本项工作为建立国内X射线水吸收剂量标准及进行国际比对提供了条件和基础。

LEGe detector intrinsic efficiency calibration for parallel incident photons.

A low energy germanium (LEGe) detector was calibrated by Monte Carlo simulation and experiment with radionuclides. At first, Monte Carlo simulations were carried out for calibrating the detector for parallel incident photons in the 1.5-180keV energy range. Then, a set of radionuclides emitting low-energy X- or γ-rays was used to calibrate the detector for quasi-parallel incident photons, which provided experimental values to compare with the simulated ones. The results show good agreement with a largest relative discrepancy of -1.8%.

Design and preliminary test of a free-air ionization chamber for low-energy X-ray

A free-air ionization chamber in low-energy X-ray has been designed and manufactured at the National Institute of Metrology (NIM, China) according to the defination of air-kerma. The results of a preliminary test show that the leakage current of ionization chamber is around 2×10−15A, and the correction factor of ion recombination for the ionization chamber is also obtained. The free-air ionization chamber is suitable for the primary standard in low-energy X-rays.