Absolute ionization cross sections for electron impact on gases relevant to the Earth's atmosphere

Data is provided for electron impact ionization and dissociation of a number of atomic and molecular gases. 
The species contain the main constitutents and trace gases in the Earth's stratosphere. 
The motivation is to provide absolute cross sections to enable the simulation of the interaction of secondary electrons produced 
by primary extraterrestrial radiation. Such simulations require accurate data for an energy range from low threshold energies 
up to several hundred electron volts (eV) of energy. Presently simulations to obtain atmospheric ionization densities use W-values 
which is the average energy required for providing an electron ion pair of the main atmospheric constituents like nitrogen. 
The data provided can be used to do more detailed and potentially more accurate calculations.