Dichroic Electron Emission Patterns from Oriented Helium Ions
Atomic Physics
2025-09-12 v2
Abstract
We report a joint experimental and theoretical study using a combination of polarization-controlled free-electron-laser (FEL) and near-infra\-red (NIR) pulses in a synchronized two-color photo\-ionization scheme. Excited He ions, created by extreme ultraviolet (XUV) circularly polarized radiation from the XUV-FEL FERMI in the oriented state, are exposed to circularly polarized 784-nm NIR radiation with peak intensities from to . The angular distribution of the ejected electrons exhibit a strong dichroism depending on the NIR intensity. While the co-rotating case is defined by a single path, for the counter-rotating case, there are two dominant pathways whose relative strength and phase difference are determined.
Cite
@article{arxiv.2507.17919,
title = {Dichroic Electron Emission Patterns from Oriented Helium Ions},
author = {Niclas Wieland and Klaus Bartschat and Filippa Dudda and René Wagner and Philipp Schmidt and Carlo Callegari and Alexander Demidovich and Giovanni De Ninno and Michele Di Fraia and Jiri Hofbrucker and Michele Manfredda and Valerija Music and Oksana Plekan and Kevin C. Prince and Daniel E. Rivas and Marco Zangrando and Nicolas Douguet and Alexei N. Grum-Grzhimailo and Michael Meyer and Markus Ilchen},
journal= {arXiv preprint arXiv:2507.17919},
year = {2025}
}