Université de Fribourg

Electron scattering in HCl: An improved nonlocal resonance model

Fedor, Juraj ; Winstead, C. ; McKoy, V. ; Čížek, M. ; Houfek, K. ; Kolorenč, P. ; Horáček, J.

In: Physcial Review A, 2010, vol. 31, no. 4, p. 042702

We present an improved nonlocal resonance model for electron-HCl collisions. The short-range part of the model is fitted to ab initio electron-scattering eigenphase sums calculated using the Schwinger multichannel method, while the long-range part is based on the ab initio potential-energy curve of the bound anion HCl-. This model significantly improves the agreement of nonlocal resonance...

Université de Fribourg

Improved nonlocal resonance model for electron – HCl collisions

Fedor, Juraj ; Kolorenč, P. ; Čižek, M. ; Horáček, J. ; Winstead, C. ; McKoy, V.

In: Journal of Physics: Conference Series, 2009, vol. 194, p. 052036

We present an improved nonlocal resonance model for electron-HCl collisions. The short-range part of the model is based on ab-initio electron scattering eigenphase sums calculated using the Schwinger Multichannel method and the long-range part on the potential curve of the bound HCl⁻ anion. We have calculated cross sections for vibrational excitation and dissociative electron attachment....

Université de Fribourg

Dissociative electron attachment to HBr: A temperature effect

Fedor, Juraj ; Cingel, M. ; Skalný, J. D. ; Scheier, P. ; Märk, T. D. ; Čížek, M. ; Kolorenč, P. ; Horáček, J.

In: Physical Review A, 2007, vol. 75, p. 022703

The effects of rovibrational temperature on dissociative electron attachment to hydrogen bromide has been investigated from the experimental and theoretical point of view. Theoretical calculations based on the nonlocal resonance model predict a strong temperature effect on the Br⁻ fragment ion yield due to population of higher vibrational and rotational states. A crossed beam experimental setup...

Université de Fribourg

Vibrational excitation of hydrogen fluoride by low-energy electrons: theory and experiment

Cízek, M. ; Horáček, J. ; Allan, Michael ; Fabrikant, I. I. ; Domcke, W.

In: Journal of Physics B: Atomic, Molecular And Optical Physics, 2003, vol. 36, no. 13, p. 2837-2849

Vibrational excitation (VE) of HF by low-energy electrons has been investigated experimentally and theoretically. A new nonlocal resonance model has been constructed based on ab initio calculations of the coupling between a discrete state and continuum states. VE and resonant elastic cross sections have been calculated for a set of initial vibrational states of the molecular target. New...

Université de Fribourg

Electron spectra for associative detachment in low-energy collisions of Cl⁻ and Br⁻ with H and D

Živanov, Svetlana ; Cížek, M. ; Horáček, J. ; Allan, Michael

In: Journal of Physics B: Atomic, Molecular and Optical Physics, 2003, vol. 36, no. 16, p. 3513-3531

Energy spectra of electrons detached in collisions of Cl⁻ and Br⁻ with atomic hydrogen and deuterium have been measured for laboratory frame ion energies between 0.2 and 8.0 eV. Their shapes agree very well with the predictions of nonlocal resonance theory. Both types of structure predicted by the theory are observed. They are the 'v steps', at ro-vibrational thresholds, and the 'S...

Université de Fribourg

Effects of interchannel coupling in associative detachment: electron spectra for H+Cl⁻ and H+Br⁻ collisions

Živanov, Svetlana ; Allan, Michael ; Cížek, M. ; Horáček, J. ; Thiel, F. A. U. ; Hotop, Hartmut

In: Physical Review Letters, 2002, vol. 89, no. 7, p. 073201

We present experimental and theoretical energy spectra of the electrons detached in collisions of slow Cl⁻ and Br⁻ ions with atomic hydrogen. Nonlocal resonance theory predicts two kinds of features in the spectra: steplike structures associated with rovibrational onsets and steep rises associated with interchannel coupling, the latter being absent in a calculation using the simpler...