B. Michel Döhring | Searcharxiv

arXiv2026

Commissioning of a fast fine-step electron-energy-scan system for electron-ion crossed-beams experiments

We report on the commissioning of a fast electron-energy scan system for measurements of electron-impact ionization cross sections. The Giessen crossed-beams experiment employs a high-power electron gun which has been developed over recent years and which permits wide variations of the beam parameters. A multi-electrode design enables the decoupling of the electron energy from the electron density. The newly implemented control system, which governs the various electrode potentials, is described together with the salient technical features.

physics.atom-ph↗

arXiv2024

Experimental and theoretical total cross sections for single and double ionization of the open-$4d$-shell ions Xe$^{12+}$, Xe$^{13+}$, and Xe$^{14+}$ by electron impact

We present new experimental and theoretical cross sections for electron-impact single ionization of Xe$^{12+}$ and Xe$^{13+}$ ions, and double ionization of Xe$^{12+}$, Xe$^{13+}$ and Xe$^{14+}$ ions for collision energies from the respective ionization thresholds up to 3500 eV. The calculations use the fully relativistic subconfiguration-averaged distorted-wave (SCADW) approach and, partly, the more detailed level-to-level distorted wave (LLDW) method. We find that, unlike in previous work, our theoretical cross sections agree with our experimental ones within the experimental uncertainties, except for the near-threshold double-ionization cross sections. We attribute this remaining discrepancy to the neglect of direct-double ionization in the present theoretical treatment.

physics.atom-ph↗