Spectroscopic data from astronomical observations obtained at ground-based or satellite observatories are analyzed with the help of spectral synthesis codes. From complex rate equation networks, based largely on theoretical plasma rate coefficients of various up- and downcharging processes, a charge state distribution is modelled and emission and absorbtion features synthesized and matched to...
In 2017, the LIGO/Virgo collaboration detected the first gravitational-wave signal from the merger of a neutron-star binary. Less than two seconds later, a network of telescopes detected a short gamma-ray burst, followed by a longer optical “afterglow” powered by the radioactive decay of the neutron-rich material ejected in the merger, i.e., a kilonova. The kilonova light-curves potentially...
A BMBF-funded free-electron target for GSI’s/FAIR’s storage rings that operates in transverse collision geometry, i.e., with an interaction angle of 90◦ between electrons and stored ions, is presently being built up and tested at the University of Giessen. The target is intended as a user facility for electron-ion collision experiments and x-ray spectroscopy with free electrons. Originally, it...
Electronic processes in ion-ion collisions are of fundamental interest from atomic physics point of view and they play an important role in astrophysical and fusion plasmas as well as in ion-matter interaction. At the same time, the ion-ion collisions are mostly unexplored up to now. This is especially true for the so-called intermediate velocity regime where the ion stopping power is maximum,...
The feasibility of high-resolution electron-ion collision spectroscopy at CRYRING@ESR of few-electron highly-charged ions from the GSI chain of accelerators has been demonstrated in a previous beam time (E131) in March 2021. In particular, it was shown that the electron-energy spread at the CRYRING electron cooler is indeed as low as expected. Building on this success, our collaboration will...
Helium-like ions are the simplest atomic multibody systems and their study along the isoelectronic sequence provides a unique testing ground for the interplay of the effects of correlation, relativity and quantum electrodynamics. However, for high-Z ions with nuclear charge Z > 54, where inner-shell transition energies reach up to 100 keV, there are currently no data available to challenge...
The proposal for measuring the reaction Ti-44(α,p)V-47 at CRYRING@ESR was granted beam time for the year 2022 in the last G-PAC (E151). However, due to various delays neither the internal gas target nor the CARME detector setup was ready and fully commissioned for successfully performing the proposed beam time. A first commissioning beam time could be performed in spring this year with one...
CARME has been successfully commissioned with beam at CRYRING in February-March 2022, in spite of some issues with the newly mounted internal target. Its science programme will be supported by an ERC Starting Grant going forward.
I will discuss our plans for the future, in terms of re-submitting proposals that have already been accepted (e.g. 2H+1H), and the potential to submit new...
We propose a systematic measurement of electron capture cross sections for heavy, bare ions at projectile energies below 5.5 MeV/u at different parameters, namely the projectile charge number, the collision energy and the target charge number. The measurement will be realized by introducing a novel internal target station setup to the CRYRING@ESR. The required diagnostic tools will be three...
One of the physics cases motivating the construction of CRYRING at the ESR was the search for NEEC through neutralization of highly-charged ions in nuclear isomeric states. The isomer of interest is 129Sb or 93Mo.
We want to continue laser spectroscopy experiments at CRYRING@ESR with Mg$^+$ ions in order to study population dynamics in the ions as well as electron-cooler ion beam dynamics.
Synchrotron oscillations in bunched beam operation lead to fast hyperfine level pumping of all velocity classes within a few revolutions. This surprising behaviour shall be further studied using laser intensity...
