Electron loss from hydrogen-like highly charged ions in collisions with electrons, protons and light atoms

Abstract

We study electron loss from a hydrogen-like highly charged ion by the impact of equivelocity electrons and protons and also in collisions with hydrogen and helium. The collision velocity v varies between vmin and vmax, where vmin and vmax correspond to the energy threshold ε th for electron loss in collisions with a free electron and to ≈ 5 ε th , respectively. Our results show that in this range of v: i) compared to equivelocity electrons protons are more effective in inducing electron loss (due to a substantially larger volume of the effectively available final-state electron momentum space), ii) the relative (compared to protons) effectiveness of electron projectiles grows with increase in the atomic number of a highly charged ion, iii) a substantial part of the volume of the final-stateelectron momentum space, kinematically available in collisions with electrons, is weaker populated in collisions with protons than with electrons, iv) even when the total loss cross sections in collisions with electrons and protons become already equal the spectra of the outgoing electrons still remain quite different in almost the entire volume of the final-state-electron momentum space. The points i) and iii), in particular, mean that in collisions with hydrogen target the contributions to the loss process from the interactions with the nucleus and the electron(s) of the atom would be to a large extent separated in the final-state-electron momentum space. arXiv:1708.08076v3 [physics.atom-ph]

Electron- and proton-impact excitation of heliumlike uranium in relativistic collisions

“…In addition, these kinds of studies can be extended to investigate the ionization of heavy few-electron ions (via proton or electron impact). Here, recent calculations predict interesting effects when looking at the momenta of the ionized electron ejected in a collision of the ion with a proton and/or an electron [41]. The corresponding experimental setup for electron spectroscopy is already available at the gas target of the ESR [42].…”

Electron-loss-to-continuum cusp in collisions of U$^{89+}$ with N$_{2}$ and Xe

“…The remaining discrepancy may motivate the development of even more sophisticated theoretical approaches of such collision systems. Our experimental and theoretical methodology can also be applied to investigate DDCS for electron-impact ionization of heavy highly-charged ions in inverse kinematics [27].…”

“…The interaction between the ionic electrons and the atomic (target) nucleus is considered within two different approximations. The first one is the first-order approximation, in which the interaction between the ionic electron and the atomic nucleus is described within the first order of perturbation theory [25,27]. The second one is the continuumdistorted-wave -eikonal-initial-state (CDW-EIS) approximation, in which this interaction is approximately taken into account in all orders [40,41].…”

“…For ν t 1, the ionization process is appropriately described by taking into account the first-order interaction between the projectile's electron and the target nucleus [23]. Fully relativistic first-order approaches are meanwhile well established [24][25][26][27][28]. In those calculations, the magnitude of the double-differential cross section (DDCS) is proportional to Z 2 t , and its shape does not depend on Z t , yielding a symmetric electron cusp shape in momentum space.…”

Radiative electron capture to the continuum in U89++N2 collisions: Experiment and theory

“…Here, the large slope in the electron energy distribution around E 0 would lead to in increased accuracy in the energy calibration in comparison to using the rather broad-usually symmetric-ELC cusp for calibration [30]. This is particularly important in collision systems, where asymmetries of the ECC cusp [33] or special cases of collision systems with an asymmetric ELC cusp [35,36] measured in parallel to the RECC are to be studied with high accuracy.…”