Research Papers in Physics and Astronomy

 

Title

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

Document Type

Article

Date of this Version

November 1969

Comments

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

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.