Inverse Bremsstrahlung with High-Intensity Radiation Fields

Abstract

The absorption of high-intensity radiation, by the inverse bremsstrahlung process, has been studied. The results are significantly modified, compared to the results of perturbation theory, when the parameter $\frac{e^2{E}^2}{m\hslash {\omega }^3}$ becomes comparable to or greater than unity. Here $E$ is the strength of the radiation electric field of frequency $\omega$. It is found that the absorption cross section changes from an inverse seven-halves-power dependence on frequency for small values of the parameter, to direct proportionality for large values. Furthermore, for large radiation fluxes, the cross section varies inversely as the three-halves power of the flux.