Influence of Intense ac Electric Fields on the Electron-Ion Collision Rate in a Plasma

The classical electron-ion collision rate, νₑᵢ, has been deduced in the absence of Ohmic heating from the inverse bremsstrahlung absorption rate measured on a laboratory plasma subjected to an intense microwave electric field E whose frequency ω is near the electron plasma frequency ωₚ. The observations, carried out in the transition range, where eE(mω)≈(kTₑm)1/2, yield a simple empirical relation that describes the decrease of νₑᵢ with increasing E.