高能电子束韧致辐射特性的理论研究

高能电子束轰击金属靶会产生韧致辐射X射线，为优化韧致辐射X射线品质，需要研究如何获取最佳辐射效率等韧致辐射规律.结合理论分析，并采用MCNP/4C对10，20?MeV电子的韧致辐射规律进行了模拟研究.讨论了不同靶材料产生的韧致辐射效率、角分布、能谱分布、准直锥孔内辐射效率等问题.通过对不同靶材料韧致辐射的模拟研究，给出了不同厚度靶与光子效率、注量分布、出射电子与角分布的关系与规律.由此得到不同靶材料对于10，20?MeV电子在最优韧致辐射效率下的一些边界条件与规律. 关键词： 韧致辐射 最佳效率 角分布 能谱

Theoretical study on bremsstrahlung of high energy electrons

Bremsstrahlung will be produced when the metal target is bombarded by high energy electrons. Bremsstrahlung characteristics is discussed under the condition of optimal bremsstrahlung efficiency for the purpose of improving its quality. This paper simulates the bremsstrahlung characteristics, combining theoretical analysis with MCNP/4C program. Electron yield characteristics, photon yield of conic collimator, angular distributions and energy spectrum distributions are simulated for targets of different thickness and materials for 10 and 20?MeV electrons. The simulation results show that photon efficiency, emitted electron and photon flux distribution is related to material and thickness of the target. And the maximum photon yield of bremsstrahlung is mainly dependent on the electron energe range, and related to atomic number. Thus the relevant boundary conditions and characteristics are obtained under the optimal bremsstrahlung efficiency of different targets for 10 and 20?MeV electrons.
Keywords： bremsstrahlung optimal efficiency angular distribution energy spectrum