MeV能量离子在生物样品中的能量损失与能量离散

Energy Loss and Straggling of MeV Energy Ions through Biological Samples

摘要: 为了研究 MeV能量离子在生物样品中的能量损失与能量离散, 分别使用1.0, 1.8和2.8 MeV质子和4.5 MeV氦离子分别辐照不同质量厚度的洋葱内表皮膜。当质子穿过该生物样品后, 可以利用透射能谱测量透射离子的能量损失和能量离散。实验结果显示, 在以上的生物样品中, MeV能量离子的能量损失值和TRIM程序模拟的结果相吻合, 但是透射离子的能量离散值却与TRIM程序模拟结果有很大的不同。结合生物样品的结构不均匀的特性, 对Bohr能量离散理论进行了修正, 并发现修正后的Bohr能量离散理论计算结果与实验值符合得很好。

Abstract: In order to study the energy loss and its straggling of MeV energy ions in biological samples, onion membrane samples with different thickness were irradiated with 1.0, 1.8, 2.8 MeV H+ and 4.5 MeV He+ , respectively. The energy loss and straggling of these ions after penetrating the biological samples were measured with transmission energy spectrum. The experimental results show that the energy losses of MeV energy ions in the biological samples mentioned above are consistent with TRIM simulation but their energy straggling are different from the simulations. Considering the inhomogeneous mass density and structure of biological materials, we modified Bohr’s energy straggling theory, and then the results are in good agreemen with the experimental energy straggling values.