关键词: 
物理性质 /
Bragg峰 /
放射治疗

摘要: 质子和重离子在现代放射治疗手段中已起着不可替代的作用， 这主要取决于其独特的物理性质。 利用一步过程和两步过程的物理模型解释了离子能量损失的机制， 同时结合Geant4软件包模拟质子和¹²C在水中的运输过程， 研究了离子束的物理性质， 并讨论了计算的结果， 说明了质子和¹²C在医学中应用的优缺点。
Depending on their unique physical properties， proton and heavy ions have taken an irreplaceable role in modern means of tumor treatment. Onestep process and twostep process physical models were employed to explain the mechanism of ion energy loss. The transport process of proton and ¹²C in water was simulated by Geant4 toolkit to study the physical properties of ion beam. The calculation results were discussed， which showed the advantages and disadvantages of proton and ¹²C in the medical application.