Department of Physics and Technology, University of Bergen, N-5007 Bergen, Norway.
Phys Rev Lett. 2010 Oct 15;105(16):163001. doi: 10.1103/PhysRevLett.105.163001. Epub 2010 Oct 12.
We develop an approximate model for the process of direct (nonsequential) two-photon double ionization of atoms. Employing the model, we calculate (generalized) total cross sections as well as energy-resolved differential cross sections of helium for photon energies ranging from 39 to 54 eV. A comparison with results of ab initio calculations reveals that the agreement is at a quantitative level. We thus demonstrate that this complex ionization process can be described by the simple model, providing insight into the underlying physical mechanism. Finally, we use the model to calculate generalized cross sections for the two-photon double ionization of neon in the nonsequential regime.
我们开发了一个用于原子直接（非顺序）双光子双电离过程的近似模型。利用该模型，我们计算了氦原子在光子能量范围从 39 到 54 eV 的情况下的（广义）总截面以及能量分辨微分截面。与从头算计算结果的比较表明，这种一致性是定量的。因此，我们证明了这个复杂的电离过程可以用简单的模型来描述，从而深入了解其潜在的物理机制。最后，我们使用该模型计算了非顺序双光子双电离氖的广义截面。
