22nd SPARC Topical Workshop

Synopsis While the interaction of atoms with particles and light has been extensively studied over the past decades, making precise and reliable predictions about the behavior and dynamics of atoms and ions remains a challenge. Serious difficulty arise not only from the complexity of most atomic processes but also from the intricate nature of inter-electronic interactions. In this work, we...

Electron spectroscopy has long been a cornerstone for studying the dynamics of ion-atom/molecule collisions [1], offering detailed insight into fundamental processes such as electron capture, ionization, and excitation [2-4]. Extending electron spectroscopy to ion-ion collisions — where both collision partners are charged — is an emerging and largely unexplored frontier. Such studies enable...

Neon, one of the most abundant elements in the universe, is frequently observed in the spectroscopic data of many astrophysical objects. Dielectronic recombination (DR) is a key process for the charge state distribution in astrophysical plasma environments. It is initiated by the resonant capture of a free electron with simultaneous excitation of a bound electron and completed by the emission...

Synopsis
Atomic cascades occur frequently in Nature and have therefore been tudied in different fields of physics and elsewhere, from precision measurements to the modeling of astrophysical spectra, and up to aterials research. We here discuss a classification of atomic cascades and shall demonstrate how such cascade processes can be readily modeled within the framework of JAC, the Jena...

The transverse electron target at the CRYRING has recently been commissioned successfully. It will allow investigating interactions between heavy ions and a collimated beam of monoenergetic electrons, including the emission of X-rays from radiative electron capture. For ions of low and medium nuclear charges, the X-ray transitions lie in the energy range of $1 – 50 \, \mathrm{keV}$. To...

C. Brandau$^{1,2}$, A. Borovik Jr.$^{1}$, B. M. Döhring$^{1,3}$, D. Banas$^{4}$, J. Glorius$^{2}$, A. Gumberidze$^{2}$, E. O. Hanu$^{2,5,6}$, P.-M. Hillenbrand$^{1,2}$, P. Jagodzinski$^{4,7}$, A. Kalinin$^{2}$, A. Krishnan$^{2,8}$, M. Lestinsky$^{2}$, M. Looshorn$^{1,3}$, E. B. Menz$^{2}$, U. Spillmann$^{2}$, K. Szary$^{4}$, R. Tyagi$^{9}$, J. Viehmann$^{9}$, S.-X. Wang$^{1,3}$, S....

The Highly charged Ions TRAP (HITRAP) located at the GSI, Darmstadt, is a facility for deceleration and cooling of ions that are produced at the accelerator complex thereby providing heavy, highly charged ions at low velocities and small energy distributions. Ion bunches consisting up to $10^{8}$ ions are injected into HITRAP at energies of 4 Mev/u from the Experimental Storage Ring (ESR),...

In modern charged particle collider research, increasing the number of investigated events requires beams with high-quality characteristics, particularly high brightness and low velocity spread. This can be achieved using beam cooling techniques. The most well-known among them is electron cooling, which involves colliding fast charged particles with a cold electron beam, resulting in a...

An Electron Beam Ion Trap (EBIT) provides highly charged ions (HCI) for spectroscopy and other experiments. To this end, a nearly monoenergetic electron beam is used. In interactions with the electrons from the beam, neutral atoms or positively charged ions can be stripped of bound electrons by means of electron impact ionisation. The electron beam originates at a so-called “electron gun”, is...

Electron-ion collision spectroscopy is a very successful approach for studying the properties of highly-charged ions [1], in particular if low-energy dielectronic recombination (DR) resonances are scrutinized. The heavy-ion storage ring CRYRING@ESR at the international FAIR facility in Darmstadt, Germany, is especially attractive for dielectronic recombination studies, since it is equipped...

Interaction of high-intensity lasers with highly charged atomic ions is
widely explored field in theory while there is still a lack in experimental data.
In the past, several experiments have analyzed high-intensity laser
ionization of gases. However, experiments of relativistic laser beams
targeting highly charged ions would allow for addressing only the
weakest bound electron in the...

Precision studies of the weak interaction in atomic systems offer sensitive tests of the Standard Model and open avenues for exploring physics beyond it. Although the landmark atomic parity violation (APV) measurements in cesium represent a key reference in the field [1], further studies are necessary. Currently, two complementary experimental approaches are being pursued: (1) large-scale...

Precise studies of the linear polarization for Compton scattered photons open the unique opportunity for a detailed test of the impulse approximation for energetic photon matter interaction. Compton scattering is the inelastic scattering of a photon off an electron, in which the scattered photon carries a lower energy than the incident photon. For scattering off bound electrons, the resulting...

Compton scattering is one of the fundamental processes in light–matter interaction in which an incoming photon is inelastically scattered off an electron. In the energy range from a few keV to several MeV, Compton scattering makes a significant contribution to the light-atom coupling. It therefore has a wide range of important applications across various fields of modern science, from...

M. Tatsch$^1$, B. M. Döhring$^{1, 2}$, K. Huber$^1$, S. Schippers$^{1,2}$
$^1$I. Physikalisches Institut, Justs-Liebig-Universität Gießen, Germany
$^2$Helmholtz Research Academy Hesse for FAIR (HFHF)

The Giessen ion source test bench is an apparatus designed to facilitate an easy adaption to a variety of different ion sources and to provide straightforward control and operation....

The well-known Auger-Meitner (AM) effect has been used extensively to study electron correlations. In ion-atom collisions, the AM process occurs during hard collisions (small impact parameter). It is known that for ions, the energy of AM e$^{-}$ shifts to the low-energy side, in contrast to X-ray energy, which shifts toward the high-energy side. For ion-atom collisions, understanding this...

S. Schippers$^{1,2}$, C. Brandau$^{1,3}$, S. Fuchs$^{1,2}$, M. Lestinsky$^{3}$, S-X. Wang$^{1,2}$, C. Y. Zhang$^{4}$, N. R. Badnell$^{4}$, A. Borovik Jr$^{1,5}$, M. Fogle$^6$, V. Hannen$^7$, Z. Harman$^{8}$, P-M. Hillenbrand$^{1,3}$, E. B. Menz$^{3,5}$, Y. Zhang$^{8,9}$, Z. Andelkovic$^3$, F. Herfurth$^{3}$, R. Heß$^3$, A. Kalinin$^3$, C. Kozhuharov$^3$, C. Krantz$^3$, S. Litvinov$^3$, B....