Correlated radiative electron capture in ion-atom collisions

TL;DR

This paper presents the first experimental evidence of radiative double electron capture (RDEC) in ion-atom collisions, demonstrating its potential as a clean probe of electron-electron interactions in electromagnetic fields.

Contribution

It reports the first experimental observation of RDEC in 38 MeV O(8+) + C collisions and compares the measured cross section with theoretical predictions.

Findings

First experimental evidence of RDEC obtained.

Measured cross section compared with theoretical models.

RDEC identified as a tool for studying electron-electron interactions.

Abstract

Radiative double electron capture (RDEC) is a one-step process where two free (or quasi-free) target electrons are captured into a bound state of the projectile, e.g. into an empty K-shell, and the energy excess is released as a single photon. This process can be treated as a time inverse of double photoionization. However, unlike in case of photoionization experiments, bare ions are used during RDEC observations. Thus, RDEC can be considered as the simplest, clean tool for investigation of the electron-electron interaction in the presence of electromagnetic fields generated during ion-atom collisions. Within this dissertation, the 38 MeV O(8+) + C experiment, conducted at Western Michigan University using the tandem Van de Graaff accelerator, is discussed and the first experimental evidence of the RDEC process is presented. The cross section obtained experimentally is compared to the latest theoretical calculations.