Highly charged ion X-rays from Electron–Cyclotron Resonance Ion Sources

Radiation from the highly charged ions contained in the plasma of Electron–Cyclotron Resonance Ion Sources (ECRISs) constitutes a very bright source of X-rays. Because the ions have a relatively low kinetic energy (≈1eV) transitions can be very narrow, containing only a small Doppler broadening. We describe preliminary accurate measurements of two and three-electron ions with Z=16–18Z=16–18. We show how these measurement can test sensitively many-body relativistic calculations or can be used as X-ray standards for precise measurements of X-ray transitions in exotic atoms.