II. Electron-impact dissociative excitation of C2H

Absolute cross-sections for electron-impact dissociative excitation of C2H2+ and C2D2+ to C2D+, CH+, C+, C2+, H+ and CH2+ singly-charged fragments have been estimated. The animated crossed-beams method is applied in the energy range from the corresponding reaction threshold up to 2.5 keV. Individual contributions for dissociative excitation are determined from the analysis of the total absolute cross-sections measured for each detected product. The dissociative excitation cross-sections are seen to decrease for more than an order of magnitude, from C2D+ (12.6±0.3)×10-17 cm2 over CH+ (6.37±0.12)×10-17 cm2, C+ (4.09±0.13)×10-17 cm2, C2+ (3.5±0.2)×10-17 cm2 and H+ (1.57±0.11)×10-17 cm2 to CH2+ (3.6±0.5)×10-18 cm2. Cross-section values and threshold energies are compared with the data which are available from the literature