We present angle- and energy-resolved measurements of photoelectrons produced in strong-field ionization of Xe using a tunable femtosecond laser. An occurrence of highly oscillatory patterns in the angular distribution at low photoelectron kinetic energy is observed that correlates with channel closing/opening over a wide range of laser parameters. The correlation is investigated both experimentally and by means of systematic analysis of numerical solutions of the time-dependent Schrödinger equation. Our experimental and numerical results are in quantitative agreement with the semi-classical model introduced by Arbó et al (2008 Phys. Rev. A 78 013406), which relates the oscillatory patterns to interference between photoelectrons produced during different cycles of the laser pulse in the course of non-resonant ionization of the atom. We observe that an increase of the laser intensity eventually leads to qualitative invariance of the pattern, defining a limit on the applicability of the semi-classical model.

J. Phys. B

Marchenko, T., Muller, H. G., Schafer, K. J., & Vrakking, M. J. J. (2010). Electron angular distributions in near-threshold atomic ionization. J. Phys. B: At., Mol. Opt. Phys., 43(9, Article number: 95601), 1–7. doi:10.1088/0953-4075/43/9/095601