Electron-impact dissociative ionization of ethylene

The ionization rates of the electron-impact ionization and dissociative ionization of ethylene for two typical cases: thermal plasmas with an electron temperature in the range between 1000 and $24\phantom{\rule{0.2em}{0ex}}000\phantom{\rule{0.3em}{0ex}}\mathrm{K}$; and nonthermal plasmas with the reduced electric field in the range between 10 and $200\phantom{\rule{0.3em}{0ex}}\mathrm{Td}$ are presented. Electron-impact dissociative ionization rates were calculated for 11 fragment ions of ethylene in the case of low temperature thermal plasma, and in a case of nonthermal ionized mixture of argon and ethylene. Dissociative ionization cross sections were calculated using a semiempirical binary-encounter bethe (BEB) model [Y. K. Kim and M. E. Rudd, Phys. Rev. A 50, 3954 (1994)], with each of the four most dominant fragments, ${\mathrm{C}}_{2}\mathrm{H}_{4}{}^{+}$, ${\mathrm{C}}_{2}\mathrm{H}_{3}{}^{+}$, ${\mathrm{C}}_{2}\mathrm{H}_{2}{}^{+}$, and ${\mathrm{H}}^{+}$, being associated with a single molecular orbital. Calculated cross sections are used in this analysis due to the fact that the existing experimental data are the least accurate in the threshold region and the calculated results can improve the accuracy in that region. Also, the procedure may be extended to molecules for which experimental data are not available.