新型平板电离室的研制与初步测试

Development and preliminary test of a novel plane-parallel ionization chamber

研制一款同时测量质子束流与剂量的平板电离室。利用基于有限元分析的Ansys模拟软件和Geant4蒙特卡罗软件对电离室电场分布、等效水厚度、不同能量质子束穿过电离室后的横向散射等参数进行模拟,进而优化电离室结构。并利用YXLON 450 kV X射线管、6 MeV脉冲加速器与北京大学串列加速器对电离室进行初步测试,电离室运行稳定,射线位置二维分布信息采集准确,性能良好。

A plane-parallel ionization chamber for position and dose detection of proton beam is developed.The ionization chamber structure is optimized by simulating the electric field distribution,equivalent water thickness,and lateral scattering of proton beams of different energies after passing through the ionization chamber using the FEM-based Ansys simulation software and Geant4 Monte Carlo toolkit.A YXLON 450 kV X-ray tube,6 MeV pulse accelerator and Peking University tandem accelerator were used to conduct preliminary tests on the ionization chamber.The ionization chamber operated stably,and the information of 2-D distribution of rays and the collection of dose information were accurate and the performance was good.