A detailed theoretical study of cascade ionization of air by rf fields and by laser beams is given. Experimental rate constants for energy loss, ionization, and attachment are used. The Boltzmann equation for the electrons is solved in both classical and quantum form. Provision is made for both single-photon and multiphoton ionization and detachment processes. The latter processes have been incorporated parametrically in our calculations owing to the lack of a quantitative description of multiphoton absorption. Possible anomalies in comparison with available experiments are noted for photons in the 1-2-eV range when the illuminated volume is large.

• Received 18 May 1971

DOI:https://doi.org/10.1103/PhysRevA.5.1883