Photoionization of excited atoms in dc gas discharges by low-intensity light and its analogy to gas-breakdown with high-intensity lasers

Spectral effects and nonlinearities that characterize illumination of dc discharges by low-intensity light and illumination of gas cells by high-intensity lasers are described. The similarities suggest an analogy between both cases. This analogy can be used to deepen the understanding of the low-intensity EM radiation interaction with gas discharges and as a possible tool for further study of gas breakdown by high-intensity lasers, including further investigation of the ''effective photon'' concept