论文标题
在强激光场中氢气样离子电离后电子动量分布的相对论掩模法
Relativistic mask method for electron momentum distributions after ionization of hydrogen-like ions in strong laser fields
论文作者
论文摘要
在光电子角分布的非相关计算中广泛使用的波函数分解或掩模方法扩展到偶极子近似中的相对论域。由于相对论沃尔科夫状态的闭合形式表达式在偶极近似中不可用，因此我们构建了这样的状态，以数值求解单个二阶微分方程。我们计算具有直接和相对论掩模方法的不同电离状态下高度电荷离子的光电能光谱和角度分布。我们表明，相对论遮罩方法效果很好，并在可以使用两种方法的能量范围内通过直接方法计算的电子能量和角度分布。另一方面，可以将相对论遮罩方法应用于更长的激光脉冲和/或较高的光电子能量，而直接方法可能会遇到困难。
Wavefunction-splitting or mask method, widely used in the non-relativistic calculations of the photoelectron angular distributions, is extended to the relativistic domain within the dipole approximation. Since the closed-form expressions for the relativistic Volkov states are not available within the dipole approximation, we build such states numerically solving a single second-order differential equation. We calculate the photoelectron energy spectra and angular distributions for highly charged ions under different ionization regimes with both the direct and the relativistic mask methods. We show that the relativistic mask method works very well and reproduces the electron energy and angular distributions calculated by the direct method in the energy range where both methods can be used. On the other hand, the relativistic mask method can be applied for longer laser pulses and/or higher photoelectron energies where the direct method may have difficulties.
