Electron-impact single and double ionization of W^{17 +}

Abstract

Abstract.A crossed-beams setup was used to measure cross sections for electron-impact single and double ionization of W 17+ ions. Absolute data and high-resolution scan spectra were obtained at collision energies ranging from threshold up to 1000 eV. Comparison of the experimental results with theoretical calculations for direct ionization suggests substantial contributions of excitation-autoionization processes to electron-impact single ionization of W 17+ .

Fusion-Related Ionization and Recombination Data for Tungsten Ions in Low to Moderately High Charge States

“…The larger DI cross section is obtained by using the CADW approach implemented in the GIPPER code which is available online (http://aphysics2.lanl.gov/cgi-bin/ION/runlanl08d.pl) on the web pages of the Los Alamos National Laboratory (LANL). error bars represent the fine energy scan of the cross-section function, the large red-shaded circles are the absolute cross section measurements to which the scan was normalized [55]. The results of the CADW calculation for the 4p, 4d, and 4f subshells of W 17+ (4f 11 ) are given by the thin black line in Figure 6 with light violet shading.…”

“…The red-shaded circles with error bars are the results of absolute cross section measurements and their total uncertainties given at a 2σ confidence level [55]. The closely spaced orange-shaded circles represent the energy-scan measurements carried out by Rausch et al [55]. The scan result is normalized to the absolute data.…”

“…E l e c t r o n e n e r g y ( e V ) Figure 7. Measured cross section for electron-impact double ionization of W 17+ ions [55].…”

Electron-impact ionization of multiply charged tungsten ions

“…Additional to absolute cross section measurements, fine-step energy scans are recorded to reveal information on indirect ionization mechanisms (see, e.g., [2]). The configuration-averaged distorted wave (CADW) approximation is employed to elucidate possible direct-ionization (DI) and excitation-autoionization (EA) contributions to the measured cross sections.…”

Tungsten Ions in Plasmas: Statistical Theory of Radiative-Collisional Processes

“…The calculation time for orders of magnitude is less than other numerical codes because the code TFATOM deals with is comprised of calculations of single or double integrals from the known Thomas-Fermi functions only. The results of comparison of the TFATOM code data for the electron impact ionization cross-sections with available series of experimental data [21][22][23][24][25][26] and the code CADW data [23,26] [21]; open triangles- [22]; full triangles-CADW data [23]; open circles [24]; full squares- [25]; dashed curves signed CADW- [26].…”