Double Core-Hole Generation in O_{2} Molecules Using an X-Ray Free-Electron Laser: Molecular-Frame Photoelectron Angular Distributions.

Gregor Kastirke,Niklas Melzer,Philipp Schmidt,Nils Rennhack,Alexander Hartung,Florian Trinter,Xiang Li,Tommaso Mazza,Nils Anders,Giammarco Nalin,Rebecca Boll,Averell Gatton,Benjamin Erk,Markus Ilchen,Daniel Rolles,Valerija Music,Artem Rudenko,Sven Grundmann,Michael Meyer,Sebastian Eckart,Maksim Kunitski,Patrik Grychtol,Andreas Pier,Daniel E Rivas,Max Kircher,Juliane Siebert,Kiyoshi Ueda,Thorsten Weber,Christian Jänke ,T Baumann ,Pawel Ziółkowski ,D Trabert ,R Dörner ,Ph V Demekhin ,L Ph H Schmidt ,N Strenger ,A De Fanis ,K Fehre ,Isabel Vela-Peréz ,J Montaño ,M Weller ,A Czasch ,Joshua Williams ,R Wagner ,M S Schöffler ,J Rist ,Y Ovcharenko ,M Hofmann ,T Jahnke

doi:10.1103/physrevlett.125.163201

Abstract

We report on a multiparticle coincidence experiment performed at the European X-ray Free-Electron Laser at the Small Quantum Systems instrument using a COLTRIMS reaction microscope. By measuring two ions and two electrons in coincidence, we investigate double core-hole generation in O_{2} molecules in the gas phase. Single-site and two-site double core holes have been identified and their molecular-frame electron angular distributions have been obtained for a breakup of the oxygen molecule into two doubly charged ions. The measured distributions are compared to results of calculations performed within the frozen- and relaxed-core Hartree-Fock approximations.

Highlights

We report on a multiparticle coincidence experiment performed at the European X-ray Free-Electron
Single-site and two-site double core holes have been identified and their molecular-frame electron angular distributions have been obtained for a breakup of the oxygen molecule into two doubly charged ions
Electrons emitted from core orbitals are local probes of the bonding and of the nearest atomic neighbors [1], which has made core-hole spectroscopy using synchrotron radiation a widely used tool in molecular physics

Summary

Introduction

Double Core-Hole Generation in O2 Molecules Using an X-Ray Free-Electron Laser: Molecular-Frame Photoelectron Angular Distributions By measuring two ions and two electrons in coincidence, we investigate double core-hole generation in O2 molecules in the gas phase. Single-site and two-site double core holes have been identified and their molecular-frame electron angular distributions have been obtained for a breakup of the oxygen molecule into two doubly charged ions.

Results

Conclusion