Quantum statistical model of nonlinear inverse bremsstrahlung absorption in strongly coupled plasmas

Abstract

A new approach for the calculation of collisional inverse bremsstrahlung absorption of laser light in dense plasmas is presented. Quantum statistical formalism used allows avoiding {\em ad hoc} cutoffs that were necessary in classical approaches. Thus, the current method remains reliable for strong electron-ion interactions. In addition, both the dynamic, field dependent response and hard electron-ion collisions, are consistently incorporated. The latter were treated in an average manner as a stopping power that in turn was cast into a form of a friction force. Here, for the first time a link between the stopping power and the problem of collisional laser absorption is drawn. This allows the theories developed for the stopping power calculation, such as the quantum T-matrix approach, to be applied to the problem of collisional laser absorption. The new approach accommodates the low- and high-frequency limits explained in the text and is valid for arbitrary laser field intensities. A comparison with classical MD simulation is indicative of the validity of the new method in the wide parameter range tested.