Measurements have been made of absolute gross ionization cross sections for 0.6-12 keV electrons in the following hydrocarbons: the series of alkanes from methane to hexane, a number of alkenes, butadiene, and benzene. A description of the experimental technique is given, the results are compared with those of other authors and the additivity of the cross sections is discussed. In all cases the energy dependence of the cross sections is in agreement with the theoretical relation: the cross section s is proportional to MI2Ee1-1 lnEe1, which gives a possibility of comparing with photoionization cross sections.
J. Chem. Phys.

Schram, B. L., van der Wiel, M. J., de Heer, F. J., & Moustafa Moussa, H. R. (1966). Absolute gross ionization cross sections for electrons (0.6-12 keV) in hydrocarbons. J. Chem. Phys., 44(1), 49–54. doi:10.1063/1.1726502