Low-energy electron scattering from water vapor

Absolute differential and integral cross section data for elastic scattering and electronic excitation of water molecules by low-energy electron impact are presented. Cross sections were obtained for the elastic and lowest lying 6 states, which dissociate to form the hydroxyl radical. The investigation is focused on OH due to its importance in living systems. The energy range of the measurements was between 1 -- 100eV for the elastic data and 9 -- 20eV for the excitation data. The absolute scale of the excitation data was established by comparison with the elastic scattering results of Khakoo et al. [1]. The present elastic data were compared to earlier data from our laboratory [1], to the data of [2] and others, to investigate a notable difference between the two sets of data. The excitation data are compared to earlier data from Thorn et al. [3] and further extend their data to near threshold energies. Important agreements and differences are observed between the two data sets and are discussed. \\[4pt] [1] M. A. Khakoo et al., Phys. Rev. A, \textbf{78}, 052710 (2008) \\[0pt] [2] H. Cho et al., J. Phys. B: At. Mol. Phys., \textbf{37} 625 (2004) \\[0pt] [3] P. A. Thorn et al., J. Phys. B.: At. Mol. Phys. \textbf{40} 697 (2007)