论文标题
X射线从线性到非线性方案的共振传播
Resonant propagation of x-rays from the linear to the nonlinear regime
论文作者
论文摘要
我们提出了一项关于通过谐振介质传播的强烈的超快X射线脉冲的时间，光谱和空间重塑的理论研究。我们的计算基于3D时间依赖性的Schrödinger-Maxwell方程的解决方案，其入射X射线光子能与核心级别的1S-3P转变在霓虹灯中。我们研究了组合入射和中产场的演变，包括刺激的发射，吸收，电离和螺旋螺旋体的影响，这是输入脉冲能量和持续时间的函数。我们发现，在核心激发状态之间刺激的拉曼散射$ 1S^{ - 1} 3p $和$ 2P^{ - 1} 3p $以高X射线强度出现，并且该频率周围的发射在包括类似的$ 1S^{ - 1} -2p^{ - 1} -2p^{ - 1} $ wendess时也会得到强烈增强。我们还探讨了X射线自我诱导的透明度（SIT）和自我关注对脉冲强度和持续时间的依赖性，我们发现受刺激的拉曼散射在这两种效应中都起着重要作用。最后，我们讨论如何将这些非线性效应可能被用作X射线自由电子激光源的脉冲特性的控制参数。
We present a theoretical study of temporal, spectral, and spatial reshaping of intense, ultrafast x-ray pulses propagating through a resonant medium. Our calculations are based on the solution of a 3D time-dependent Schrödinger-Maxwell equation, with the incident x-ray photon energy on resonance with the core-level 1s-3p transition in neon. We study the evolution of the combined incident and medium-generated field, including the effects of stimulated emission, absorption, ionization and Auger decay, as a function of the input pulse energy and duration. We find that stimulated Raman scattering between core-excited states $1s^{-1}3p$ and $2p^{-1}3p$ occurs at high x-ray intensity, and that the emission around this frequency is strongly enhanced when also including the similar $1s^{-1}-2p^{-1}$ response of the ion. We also explore the dependence of x-ray self-induced transparency (SIT) and self-focusing on the pulse intensity and duration, and we find that the stimulated Raman scattering plays an important role in both effects. Finally, we discuss how these nonlinear effects may potentially be exploited as control parameters for pulse properties of x-ray free-electron laser sources.
