Electron dose calculation using multiple-scattering theory: energy distribution due to multiple scattering.
Electron dose calculation using multiple-scattering theory: energy distribution due to multiple scattering.
复制标题
使用多重散射理论计算电子剂量：多重散射引起的能量分布。
DOI：
10.1118/1.597907
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发表时间：
1997
期刊：
影响因子：
3.8
通讯作者：
Walker,S
中科院分区：
文献类型：
--
作者：
Jette,D;Walker,S
1951年，杨振宁推导出了计算粒子穿过箔片的路径长度分布的公式，只考虑了多次散射过程。我们在这里通过使用二阶小角度近似来提高这项工作的精度。我们推导出了宽平行光束的一般解，并找到了杨的两种特殊情况下的简单公式：在一个特定点上的所有粒子的路径长度分布，一起;和在一个特定点上的路径长度分布只有那些粒子与零净角偏转。从光程（或剩余光程）分布，可以立即推导出剩余射程和能量分布。所有这些工作假设相对较小的能量损失，我们认为5兆电子穿透铅，这提供了相当大的散射没有主要的能量损失。发现二阶能量分布与（一阶）杨能量分布有很大不同，并且与EGS 4蒙特卡罗计算更接近。
In 1951, Yang derived formulas for computing the pathlength distribution of particles traversing foils, considering only the multiple‐scattering process. We here improve upon the accuracy of that work, by using our second‐order small‐angle approximation. We derive the general solution for a broad parallel beam, and find simple formulas for Yang's two special cases: the pathlength distribution of all the particles at a particular point, taken together; and the pathlength distribution at a particular point of only those particles with zero net angular deflection. From the pathlength (or excess pathlength) distribution, residual range and energy distributions can immediately be deduced. All this work assumes relatively small energy loss, and we consider 5 MeV electrons penetrating lead, which provides considerable scattering without major energy loss. The second‐order energy distribution is found to differ considerably from the (first‐order) Yang energy distribution, and to agree more closely withEGS4Monte Carlo calculations.