SPARC-Call for Proposals for beamtime in 2023/2024

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...

Obtaining reliable cross sections for neutron-induced reactions on unstable nuclei is a highly important task and a major challenge. These data are essential for understanding the synthesis of heavy elements in stars and for applications in nuclear technology. However, their measurement is very complicated as both projectile and target are radioactive. The best alternative to infer these cross...

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...