Dielectric Theory of Collisional Absorption in Intense Laser Fields

Collisional absorption of superintense laser pulses in dense plasmas can be described by the classical linear dielectric theory in a wide range of parameters. For electron oscillation velocities largely exceeding their thermal motion a linear oscillator model is presented and nearly exact solutions in terms of Anger functions are given for the time‐averaged electron‐ion collision frequency. A possible extension of the dielectric theory into higher density and/or lower temperature regions is indicated and the need for time‐dependent collision frequencies is stressed.