Complete Experiments in Electron-Atom Collisions

Resonance and Threshold Phenomena in Low-Energy Electron Collisions with Molecules and Clusters

“…A wealth of information has been gained on the dynamics of these collisions, as documented by many reviews and books (e.g. Schulz, 1973a, b;Lane, 1980;Trajmar et al, 1983;Christophorou, 1984;Shimamura and Takayanagi, 1984;Allan, 1989;Domcke, 1991;Buckman and Clark, 1994;Crompton, 1994;Filippelli et al, 1994;Trajmar et al, 1994;Huo and Gianturco, 1995;Andersen and Bartschat, 1996;Chutjian et al, 1996;Zecca et al, 1996;Becker et al, 2000;Illenberger, 2000;Winstead and McKoy, 2000;Christophorou and Olthoff, 2001a, b;Karwacz et al, 2001a, b;Brunger and Buckman, 2002). In spite of this progress, however, the exploration of threshold phenomena in electronmolecule collisions at low energies -both in the limit of zero electron energy and in the neighborhood of onsets for vibrational excitation -has remained a major challenge for experiment and theory.…”

Resonance and Threshold Phenomena in Low-Energy Electron Collisions with Molecules and Clusters

“…A wealth of information has been gained on the dynamics of these collisions, as documented by many reviews and books (e.g. Schulz, 1973a, b;Lane, 1980;Trajmar et al, 1983;Christophorou, 1984;Shimamura and Takayanagi, 1984;Allan, 1989;Domcke, 1991;Buckman and Clark, 1994;Crompton, 1994;Filippelli et al, 1994;Trajmar et al, 1994;Huo and Gianturco, 1995;Andersen and Bartschat, 1996;Chutjian et al, 1996;Zecca et al, 1996;Becker et al, 2000;Illenberger, 2000;Winstead and McKoy, 2000;Christophorou and Olthoff, 2001a, b;Karwacz et al, 2001a, b;Brunger and Buckman, 2002). In spite of this progress, however, the exploration of threshold phenomena in electronmolecule collisions at low energies -both in the limit of zero electron energy and in the neighborhood of onsets for vibrational excitation -has remained a major challenge for experiment and theory.…”

Comparison of experiment and theory for superelastic electron-collision studies from laser-aligned magnesium

“…By defining a scattering plane by the momenta of the incident and scattered electrons (k in , k out ), the scattering amplitudes can be calculated in the "natural" frame, where the quantization axis is chosen to be perpendicular to the plane (see Fig. 1) [34]. For excitation of a P state the scattering amplitudes in this frame are given by f Nat ±1,0 .…”

“…1(a)]. The linear Stokes parameters then can be related to the alignment parameters (P , γ ), and the circular Stokes parameter is directly related to L ⊥ [34]. Since the majority of photons from the excited targets are not emitted in the direction of the photomultiplier tube, the accumulation of true coincidence counts is slow, and so these are very time-consuming measurements.…”

“…This process is equivalent to measuring the polarization of the emitted photon in coincidence studies. Both types of experiment generate a set of atomic collision parameters (ACPs) [3,34] that define the alignment and orientation of the excited atoms due to the collision; however, the data collection rates are thousands of times faster in superelastic experiments than for coincidence studies. The ACPs are directly related to the real and imaginary parts of the scattering amplitudes, as discussed in Sec.…”