Wirkungsquerschnitte für die Anregung von Molekülschwingungen durch schnelle Elektronen

Abstract

The differential cross section for the excitation of infra-red inactive and — in dipole approximation — infra-red active fundamental vibrations by fast electrons is calculated. The energy loss spectra of CO₂, N₂O, C₂H₄ are measured with 33 keV electrons in the small energy loss range up to 0.5 eV. The experimentally determined “particular” cross sections

$$\sigma = \int\limits_{\vartheta = 0}^{1.1 \cdot 10^{ - 4} } {d\sigma }$$

for the excitation of active fundamental molecular vibrations which are of order 10⁻²¹ cm² agree well with values calculated from the integrated absorption intensity of the corresponding rotation-vibration bands.