摘要
从高能电子在多成分介质中输运的Ｂｏｌｔｚｍａｎｎ方程出发，采用Ｆｏｋｋｅｒ－Ｐｌａｎｃｋ近似导出电子束能量分布的高斯谱，对连续慢化近似（ＣＳＤＡ）进行修正从而引入修正的ＣＳＤＡ平均能量，并采用杨振宁的多次散射理论，最后给出一个计算高能电子束平均能量的递推一迭代算法。并给出了由该算法得出的部分计算结果，并与相应的Ｍｏｎｔｅ－Ｃａｒｌｏ模拟及实验测量作了比较，比较的结果表明该算法能够较为精确地计算高能电子束在轻介质中的平均能量变化。此外，还讨论了在辐射洽疗剂量算法中最常见的电子束平均能量计算公式，即Ｈａｒｄｅｒ公式和Ｂｒａｈｍｅ公式，并提出了一个较这两个公式更为精确的半经验公式。
In this paper a, Gaussian distributioll,for electron energy, is. deduced by Fokker-Planck approximation to the Boltzmann equation for high-energy electrons penptrating in multi-constituents media, then a recursin-iteration, algorithm for the mean energy leaiculation of hish-energy.electron beam is obtained after introducing the modified CSDA mean energy and uking Yang'a mtltipole scattering. theory.Some calculational results of. this algorithm are also given in the article and compared with corresponding data of Monte Carlo siamultions, and experimental mea measurements. The comparison shows that the algorithm can precisely predict the coenergy of high-energy electron beam penetrating in light media. Furthermore, two common forinulae for electron beam mean energy calculation in radiotherapy dosealgorithms. i. e., the Harder formula and Brahme.formula, are discussed ;and a more accurate semi-empirinal formula is recommended in this paper as well.
出处
《辐射研究与辐射工艺学报》
CAS
CSCD
北大核心
1994年第4期232-238,213,共8页
Journal of Radiation Research and Radiation Processing
关键词
电子束平均能量
辐射治疗
辐射剂量
Mean energy of electron beam, Radiotherapy, Radiation doses Electron beam dosimetry
