Absolute vibrational differential cross sections of water vapor by 30 and 50 eV electron impact

Direct vibrational excitation of water vapor has been investigated by use of electron impact spectroscopy. Absolute vibrational differential cross sections have been measured for the bending (010) and stretching (100,001) modes of the electronic ground state at 30 and 50 eV impact energies and in the angular range from 10° to 60°. Our experimental data are compared to theoretical results available in the literature.