Vibrational Excitation by Electron Impact near Threshold in H₂, D₂, N₂, and CO

Authors

Paul Burrow, Universit y of Nebraska - LincolnFollow
G.J. Schulz, Mason Laboratory, Yale University, New Haven, Connecticut

Date of this Version

November 1969

Comments

Phys. Rev. 187, 97 (1969). Copyright © 1969. Permission to use. http://prola.aps.org/ .

Abstract

The trapped-electron method is applied to the measurement of the slopes of the vibrational cross sections near their respective thresholds. Absolute values are obtained by normalization to positive-ion cross sections. The values obtained in H₂ are 43 for v=1, 0.72, for v=2, 0.04, for v=3, and 0.003, for v=4, in units of 10^-18 cm²/eV. The values for N₂ are 2.5 for v=1 and about 0.02 for v=2, whereas, the values for CO are much larger, i.e., 120 for v=1 and 2.4 for v=2. Various corrections that are necessary for determining absolute cross sections from trapped-electron data are discussed. The validity of the corrections is studied for the case of the 2³S excitation function in He.