Electron and positron scattering from the benzene derivative: Toluene

Abstract

Electron and positron cross sections for scattering from toluene molecules have been investigated both experimentally and theoretically over the energy range 0.4-1000 eV. Peaks have been observed in the electron total cross sections (TCSs) at 1.4, 4.5, and 8.0 and a shoulder at about 40 eV. Vibrational and elastic differential cross section experiments were carried out to probe the origin and nature of these peaks. The continuum multiple scattering method was used to calculate elastic integral cross sections for electron impact. Although the 1.4 eV peak is dominated by the elastic channel, strong contributions from the CH3 asymmetric bending and stretching vibrational modes are also observed. The 4.5 eV feature is also observed to be strongly due to vibrational excitation. The broad 7-13 eV peak includes contributions from the CH3 asymmetric bending (peaked at 7 eV) and the CH3 stretching (peaked at 9.5 eV) vibrational modes. Positron TCSs are studied and compared to positron-benzene TCSs. The effect of the CH3 substitution is observed to make a significant contribution to both electron and positron TCSs below 20 eV.