矩形均匀电子束在激光介质中的能量沉积的模拟计算

SIMULATIONS OF ENERGY DEPOSITION OF ELECTRON BEAMSIN LASER MEDIUMS

本文主要论述了0.5MeV,单能垂直入射的电子束在三种不同密度的氟化氪准分子激光介质中的能量沉积。计算是采用Monte Carlo方法的MCSED程序,光轴方向采用周期性边界条件,因此能够给出平行于和垂直于电子束入射方向的沉积能量的空间分布。本文给出了在三种不同密度下的出射电子的角分布。用该程序对垂直入射的,初始能量为1MeV的电子在半无限大Al靶中的沉积能量的计算结果与ONETRAN程序的结果及实验结果的比较表明MCSED程序的计算结果是可靠的。

Energy deposition of a normally incident 0-5MeV electron beam in KrF laser media was simulated using Monte carlo method, a periodic boundury condition was used along the laser axis.The spatial distributions of energy deposition both parallel and perpendicular to electron beam were obtaned The continue -slow-down approximation was adopted for energy losses of electrons,and Goudsmit-Saunderson angle distribution theory was used to calculate themulti-scattering angle distribution of the incident electrons. The laser medium contains 89.6% of Ar, 10% of Kr and 0.4% of F2.Because the component of fluorine was very small, the energy deposited in flourine was neglected. The total deposited energy in the laser medium with 0.001813g/cm3 density was about 4.34% of the initial energy; 0.003658g/cm3 density, 9-11%; 0.001813g/cm3 density. 11.53%. Meanwhile the angle distributions of outgoing electrons scattered through Kr and Ar with different densities were also obtained. The computed results of electron deposition in semi-infinite Al target were consistent with those of ONETRAN code and experiment results.