Absolute cross sections forH+formation from electron-impact dissociation ofC2H+andC2H2+

Abstract

Absolute cross sections as a function of interaction energy were measured for ${\mathrm{H}}^{+}$ formation in electron-impact dissociation of ${\mathrm{C}}_{2}{\mathrm{H}}^{+}$ and ${\mathrm{C}}_{2}{\mathrm{H}}_{2}^{+}$ in the energy range from threshold up to 50 eV. The crossed beams technique was used, and light fragment ions emerging from a heavy target were detected. A common feature of the studied targets was almost the same $[(1.3--1.7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16} {\mathrm{cm}}^{2}]$ cross section for ${\mathrm{H}}^{+}$ production from 25 to 50 eV. The results were compared with our previous results for ${\mathrm{CD}}_{n}^{+},$ and the observed propensity rules were found to apply in this case also.