Electron impact excitation of Ni-like gold studied by Dirac R-matrix method

We calculate the electron impact excitation of Ni-like gold by using the Dirac R-matrix theory, and the corresponding collision strengths and effective collision strengths are obtained. In the calculations of the level energy,(1s22s22p6)3s23p63d10, 3s23p63d94 l, 3s23p53d104 l, and 3s3p63d104l(l = 0,1,2,3) configurations are included and 107fine-structure levels are generated. In the calculations of the collision strengths, only the first 59 levels are included. Comparisons are made with the distorted wave(DW) results of Zeng et al. for both collision strengths and effective collision strengths. For the collision strengths, the two sets of calculations are in excellent agreement for most of the transitions.However, because of the inclusion of the resonances, our effective collision strengths are generally several times larger than those of Zeng et al.. The accuracy of our calculations is assessed.     

相位型波带板应用于大尺度X射线源成像的分析与模拟

针对大尺度物体的keV-X射线高分辨成像,分析了相位型菲涅耳波带板(FPZP)对物平面1mm区域内点源的成像,确定像的空间分布具有不变性,提出了一种FPZP对扩展光源成像的计算方法.使用这一方法,模拟了放大倍数为10的典型实验条件下最外环宽0.35 μm的FPZ对扩展单色光源的成像.结果表明,随着扩展光源尺度的增加,像的对比度降低.FPZP的负1级和0级衍射是导致像的背景增强和对比度降低的主要因素,并相应导致成像对物方的空间分辨能力下降.对于强度空间分布为正弦调制、对比度为1的1mm尺度方形光源,像的对比度低于0.4,物方分辨能力为0.75 μm.