论文标题
1D光子晶体中X射线脉冲扩增的Maxwell-Bloch建模
Maxwell-Bloch modeling of an x-ray pulse amplification in a 1D photonic crystal
论文作者
论文摘要
我们介绍了Maxwell-Bloch（MB）形式主义的实施，以研究定期多层材料的X射线发射动力学，无论它们是人造的还是自然的。该处理是基于麦克斯韦方程与包含随机自发发射噪声的Bloch方程的直接有限差分域（FDTD）解决方案。除了材料的周期性外，处理还区分了两种层，那些是活跃的（或共振）和那些差异的层。数值模型应用于多层材料中$kα$发射的问题，在这些问题中，可以通过X射线自由电子激光器（XFEL）快速内部壳光电离来创建种群反演。数值模拟说明了在布拉格衍射条件下产生的放大荧光的特异性。相应的脉冲可用于特定研究X射线与物质的非线性相互作用。
We present an implementation of the Maxwell-Bloch (MB) formalism for the study of x-ray emission dynamics from periodic multilayer materials whether they are artificial or natural. The treatment is based on a direct Finite-Difference-Time-Domain (FDTD) solution of Maxwell equations combined with Bloch equations incorporating a random spontaneous emission noise. Besides periodicity of the material, the treatment distinguishes between two kinds of layers, those being active (or resonant) and those being off-resonance. The numerical model is applied to the problem of $Kα$ emission in multilayer materials where the population inversion could be created by fast inner-shell photoionization by an x-ray free-electron-laser (XFEL). Specificities of the resulting amplified fluorescence in conditions of Bragg diffraction is illustrated by numerical simulations. The corresponding pulses could be used for specific investigations of non-linear interaction of x-rays with matter.
