Relativistic, QED and nuclear effects in highly charged ions revealed by resonant electron-ion recombination in storage rings

TL;DR

This paper reviews recent advances in high-resolution spectroscopic techniques for highly charged ions, demonstrating sensitivity to quantum electrodynamics and nuclear effects through resonant electron-ion recombination in storage rings.

Contribution

It highlights new experimental methods and findings that reveal QED and nuclear effects in highly charged ions using resonant electron-ion recombination.

Findings

Detection of 2nd order QED effects in highly charged ions

Observation of isotope shifts in DR resonances

Measurement of hyperfine induced decay rates

Abstract

Dielectronic recombination (DR) of few-electron ions has evolved into a sensitive spectroscopic tool for highly charged ions. This is due to technological advances in electron-beam preparation and ion-beam cooling techniques at heavy-ion storage rings. Recent experiments prove unambiguously that DR collision spectroscopy has become sensitive to 2nd order QED and to nuclear effects. This review discusses the most recent developments in high-resolution spectroscopy of low-energy DR resonances, experimental studies of KLL DR of very heavy hydrogenlike ions, isotope shift measurements of DR resonances, and the experimental determination of hyperfine induced decay rates in divalent ions utilizing DR.