Laser spectroscopy of the $^2S_{1/2} - ^2P_{1/2}$, $^2P_{3/2}$ transitions in stored and cooled relativistic C$^{3+}$ ions

TL;DR

This study used advanced laser spectroscopy techniques to measure specific electronic transitions in relativistic C$^{3+}$ ions, confirming theoretical predictions and resolving previous experimental discrepancies.

Contribution

It introduces a new UV laser system and XUV detection method for precise measurements of ion transitions at relativistic speeds.

Findings

Confirmed theoretical transition wavelengths for C$^{3+}$ ions.

Resolved discrepancies from earlier ESR measurements.

Achieved high-precision spectroscopy at relativistic velocities.

Abstract

The $^2S_{1/2} - ^2P_{1/2}$ and $^2S_{1/2} - ^2P_{3/2}$ transitions in Li-like carbon ions stored and cooled at a velocity of $\beta \approx 0.47$ in the Experimental Storage Ring (ESR) at the GSI Helmholtz Centre in Darmstadt have been investigated in a laser spectroscopy experiment. Resonance wavelengths were obtained using a new continuous-wave UV laser system and a novel extreme UV (XUV) detection system to detect forward emitted fluorescence photons. The results obtained for the two transitions are compared to existing experimental and theoretical data. A discrepancy found in an earlier laser spectroscopy measurement at the ESR with results from plasma spectroscopy and interferometry has been resolved and agreement between experiment and theory is confirmed.