机构地区: 中国科学院西安光学精密机械研究所
出 处: 《计算物理》 2003年第1期21-24,共4页
摘 要: 轰击金属靶面的高能电子束束斑大小,是决定微束斑X射线源最终X射线束斑尺寸的关键因素之一.当LaB6晶体阴极发射电流为60μA时,采用5点不等距有限差分法(FDM)计算了整个仪器内旋转对称电子光学系统电场的分布,并利用Runge Kutta法从LaB6阴极发射端面开始追踪了电子束在整个系统内部的运动,经计算,聚焦在靶面上的电子束斑直径约为600~1000nm. The focal dimension of the Xray source with microbeam is in proportion to the size of the ebeam focused on the target surface. The finite difference method is utilized to calculate the distribution of the electricalfield intensity. The track of the electronbeam is traced by using the RungeKutta method within the whole symmetrical system. As a result, the diameter of the electron beam focus is 06-10?μm while the total high brightness emission of the LaB6 crystal cathode is 006-03?mA.