Periodic bursts of stimulated Brillouin backscattering in the process of laser beam self-focusing in plasma

Abstract

The simultaneous dynamics of self-focusing and stimulated Brillouin back scattering (SBBS) is investigated. It is shown that scattered radiation appears as the high intensity periodical bursts by nonstationary self-focusing of incident beam. However, the time averaged level of scattered radiation is quite low. The important feature of the reviled self-adjustment SBBS regime is a weak dependence of the time averaged reflection coefficient as on pump wave intensity so as on spontaneous level of reflected wave that is in accordance with many laser-plasma experiments.