Quantum Theory of Inverse Bremsstrahlung Absorption and Pair Production

Abstract

The inverse Bremsstrahlung process is believed to play an important role in the heating of plasma electrons by laser radiation. In this process, an electron absorbs energy from the laser beam during a collision with a nucleus. From a classical viewpoint, the electron oscillates in the electric field of the laser beam. During a collision with a nucleus, the electron is knocked out of phase with the electric field, and the oscillatory energy of the electron is converted to random thermal energy. From a quantum viewpoint, the electron can gain energy only in units of ħω, where ω is the frequency of the laser radiation, and it is not clear that the classical theory is valid. In this paper, we discuss the quantum theory of inverse Bremsstrahlung absorption, and compare the quantum results to the classical results.