几种不同材料降能器对 200 MeV 质子放疗特性的蒙特卡罗模拟

本文利用蒙特卡罗软件TOPAS模拟200MeV质子在石墨、铍和碳化硼三种不同材料多楔形结构降能器中的输运过程，统计了穿过降能器后质子以及产生的次级中子的能量通量，并计算了质子束流在穿过不同降能器后的能量分散，据此得到了三种材料降能器厚度与质子能量之间的关系曲线，同时也分析了不同降能器对质子束传输效率的影响以...

This study employed the Monte Carlo simulation code TOPAS to simulate the transport process of 200 MeV protons through multi-wedge structure degraders made of three distinct materials: graphite, beryllium, and boron carbide. We tallied the energy fluences of the transmitted protons and the generated secondary neutrons, and calculated the energy spread of the proton beam after passing through each degrader. Based on the obtained data, we derived the correlation curves between the degrader thickness and the emergent proton energy for each material, and also analyzed the effects of different degraders on the transmission efficiency of the proton beam, and so on.