Cross sections for short pulse single and double ionization of helium

TL;DR

This paper demonstrates accurate methods for extracting ionization amplitudes from wavepackets, effectively describing two-photon single and one-photon double ionization of helium, including autoionizing state features.

Contribution

It introduces and validates procedures for unambiguously extracting ionization amplitudes from time-dependent wavepackets for helium ionization processes.

Findings

Methods accurately resolve autoionizing states.

Procedures effectively describe two-photon and one-photon ionization.

Wavepacket propagation yields clear ionization amplitude extraction.

Abstract

In a previous publication, procedures were proposed for unambiguously extracting amplitudes for single and double ionization from a time-dependent wavepacket by effectively propagating for an infinite time following a radiation pulse. Here we demonstrate the accuracy and utility of those methods for describing two-photon single and one-photon double ionization of helium. In particular it is shown how narrow features corresponding to autoionizing states are easily resolved with these methods.