Measurement of near-threshold vibrational excitation of HCl by electron impact

Abstract

Relative differential cross sections (sum of 0 and 180' scattering) have been measured for excitation of the vibrational levels of HCl up to v=5 by impact of electrons at energies from threshold to 3 eV above. Pronounced threshold peaks are observed in the excitation of v=1 and v=2, but not for the higher levels. The shapes of the cross sections agree well with the results of several published theoretical studies. The unexpected experimental observation of 'boomerang' vibrational structure by Cvejanovic et al. (1989) in the v=1 channel has been confirmed.