Coulomb Divergence in S-Matrix Expansion of Above-Threshold Ionization

Authors

  • Mingqing Liu Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100088, China
  • Zheng Shu Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100088, China
  • Bobin Li HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100084, China
  • Shilin Hu TianQin Research Center & School of Physics and Astronomy, Sun Yat Sen University (Zhuhai Campus), Zhuhai 519082, China
  • Jing Chen Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100088, China

DOI:

https://doi.org/10.4208/jams.050517.072017a

Keywords:

above-threshold ionization, S-matrix thoery, Coulomb optential, rescattering.

Abstract

Photoelectron spectrum of above-threshold ionization (ATI) is calculated using the first two orders of Coulomb-Volkov S-matrix series (Faisal, Phys. Rev. A 94, 031401 (2016)). Calculation shows that Coulomb divergence, due to singularity of forward scattering, still exists in the first two order terms for an unscreened Coulomb potential. This divergence can be removed by adding a decay factor into the phase of the S-matrix element which comes from depletion of the atomic ground state. We show that by using an example of hydrogen atom, the Coulomb-Volkov S-matrix series can successfully describe the energy spectrum of ATI and high-order ATI with the introduction of a deplete rate of the ground state.

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Published

2017-08-01

Issue

Vol. 8 No. 1 (2017)

Section

Articles