Collinear laser spectroscopy in the $1s2s{}^3{\mathrm{S}}_1\to 1s2p{}^3{\mathrm{P}}_{0,2}$ transitions of helium-like ${}^{11}$B${}^{3+}$ was performed using the HITRAP beamline at the GSI Helmholtz Centre. The ions were produced in an electron beam ion source, extracted, and accelerated to a beam energy of 4 keV/q. Results agree with previous measurements within uncertainty. Thus, it was demonstrated that the metastable state in He-like ions is sufficiently populated to carry out collinear laser spectroscopy. The measurement is a pilot experiment for a series of measurements that will be performed at a dedicated collinear laser spectroscopy setup at TU Darmstadt with light helium-like ions.

We present a recently established setup for laser spectroscopy at CRYRING@ESR at the GSI Helmholtz Centre for Heavy Ion Research. Here, laser spectroscopy can be performed on stored and cooled ion bunches and coasting beams. First spectra of ^24,25Mg⁺ ions are presented that were recorded by classical Doppler-limited fluorescence spectroscopy as well as Λ-spectroscopy using counter- and copropagating laser beams that are Doppler-shifted by several nm.

The most efficient and most versatile technique for producing highly charged ions (HCI) with high atomic numbers is electron stripping in-flight at high kinetic energies. While this requires relativistic velocities, many experiments call for trapped or at least slowly moving ions. For example, studies of fundamental interactions would significantly improve in precision when performed in an ion trap while studies on slow HCI for material science are not yet feasible due to the lack of availability. The goal of the HITRAP project at the GSI Helmholtzzentrum für Schwerionenforschung GmbH is to decelerate accelerator-produced heavy HCI and prepare them in a Penning trap via electron cooling for subsequent experiments. We present the trapping of accelerator-produced HCI. Fully stripped Ar 36 18 + were decelerated from the production energy of 45 MeV / u to 6 keV / u followed by trapping in the HITRAP Cooling Trap for the duration of several seconds. The Cooling Trap is a nested Penning trap that allows for the simultaneous storage of HCI ions with a cold electron plasma. It was commissioned with HCI from a local electron beam ion source, which led to the first observation of electron cooling of highly charged ions in a Penning trap, marking a significant advancement in the field. These developments constitute a major step toward a worldwide unique facility with unparalleled capabilities in heavy-ion research and already enable the first experimental studies at HITRAP.