Laser-assisted electron-argon scattering at small angles

TL;DR

This paper theoretically investigates laser-assisted electron-argon scattering at small angles, using advanced computational methods to assess the role of long-range interactions and compare with experimental results.

Contribution

It introduces a Floquet R matrix approach with an extended reaction volume to evaluate the impact of polarization potential on scattering cross sections.

Findings

Long-range polarization potential does not significantly affect cross sections.

Theoretical cross sections do not match the high experimental values.

The Kroll-Watson approximation may not be valid at small angles.

Abstract

Electron-argon scattering in the presence of a linearly polarized, low frequency laser field is studied theoretically. The scattering geometries of interest are small angles where momentum transfer is nearly perpendicular to the field, which is where the Kroll-Watson approximation has the potential to break down. The Floquet R matrix method solves the velocity gauge Schr\"odinger equation, using a larger reaction volume than previous treatments in order to carefully assess the importance of the long range polarization potential to the cross section. A comparison of the cross sections calculated with the target potential fully included inside 20 and 100 a.u. shows no appreciable differences, which demonstrates that the long range interaction can not account for the high cross sections measured in experiments.