Absolute cross sections and kinetic energy release distributions for electron-impact ionization and dissociation of CD+ 4

Abstract

Absolute cross sections for electron-impact dissociative excitation and ionization of CD+ 4 leading to formation of ionic products (CD2+ 4, CD+ 3, CD+ 2, CD+, C+, D+ 3, D+ 2, and D+) have been measured. The animated crossed-beams method is applied in the energy range from the reaction threshold up to 2.5 keV. Around 100 eV, the maximum cross sections are found to be (3.8±0.2) ×10-19 cm2, (10.8±1.5)× 10−17 cm2, (7.1±0.8) ×10-17 cm2, (9.0±0.8) × 10-17 cm2 and (3.7±0.4) ×10-17 cm2 for the heavy carbonaceous ions CD2+ 4, CD+ 3, CD+ 2, CD+ and C+ respectively. For the light fragments, D+ 3, D+ 2, and D+, the cross sections around the maximum are found to be (5.0±0.6) ×10-19 cm2, (1.7± 0.2) ×10-17 cm2 and (10.6±1.0) ×10-17 cm2, respectively. The cross sections are presented in closed analytic forms convenient for implementation in plasma simulation codes. The analysis of ionic product velocity distributions allows determination of the kinetic energy release distributions which are seen to extend from 0 to 9 eV for heavy fragments, and up to 14 eV for light ones. The comparison of present energy thresholds and kinetic energy release with available published data gives information about states contributing to the observed processes. Individual contributions for dissociative excitation and dissociative ionization are determined for each detected product. A complete database including cross sections and energies is compiled for use in fusion application.