Absolute partial and total electron impact ionization cross sections for C 2H 6 from threshold up to 950 eV

Abstract

Electron impact ionization of ethane (C 2H 6) was studied with a modified Nier type ion source and a double focussing mass spectrometer (reversed geometry). Using the ion-beam-deflection-technique and a SIMION based correction procedure it is possible to determine accurately parent and fragment ion currents produced. This allows the determination of relative partial ionization cross section functions from threshold up to 950 eV for the production of C 2H + 6, C 2H + 5, C 2H + 4, C 2H + 3 C 2H + 2, C 2H +, C + 2; Ch + 3, CH + 2, CH +, C +; C 2H 2+ 5 and C 2H 2+ 3, respectively. Absolute partial ionization cross section functions for these ions were obtained by charge-weighted summing of all the observed partial ionization cross sections and by normalizing to be absolute total ionization cross section at 100 eV reported recently by Djuric. [N. Djuric, I. Cadez and M. Kurepa, Int. J. Mass Spectrom. Ion Processes 108 (1991) R1]. Comparisons are made to earlier measurements.