# Photoionization of ions with synchrotron radiation: From ions in space to atoms in cages

## TL;DR

This paper introduces the photon-ion merged-beams technique for studying photoionization of ions using synchrotron radiation, covering fundamental mechanisms and applications in astrophysics, plasma physics, and nanoparticle research.

## Contribution

It presents a comprehensive overview of the photon-ion merged-beams method and demonstrates its capabilities across various complex ion systems and applications.

## Key findings

- Elucidation of fundamental ionization mechanisms
- Application to astrophysics and plasma physics
- Study of photoabsorption in nanoparticles

## Abstract

The photon-ion merged-beams technique for the photoionization of mass/charge selected ionized atoms, molecules and clusters by x-rays from synchrotron radiation sources is introduced. Examples for photoionization of atomic ions are discussed by going from outer-shell ionization of simple few-electron systems to inner-shell ionization of complex many-electron ions. Fundamental ionization mechanisms are elucidated and the importance of the results for applications in astrophysics and plasma physics is pointed out. Finally, the unique capabilities of the photon-ion merged-beams technique for the study of photoabsorption by nanoparticles are demonstrated by the example of endohedral fullerene ions.