Photon Landau damping of relativistic plasma waves

摘要

Photon Landau damping of electron plasma waves with relativistic phase velocity has been first considered in 1997, in the frame of geometric optics [1]. Here we consider more recent results based on a kinetic model where photon recoil is taken into account [2]. By photon recoil we mean the change of a finite amount of momentum by photons, due to the emission or the absorption of electron plasma waves. This gives a surprising quantum flavor to a purely classical description. Our approach is based on an exact form of the wave kinetic equation. Kinetic and fluid regimes of photon beam instabilities, and their relevance to particle acceleration and new radiation sources are discussed. Quasi-lnear results leading to a photon Boltzmann equation are also discussed. Diffusion in the photon momentum space are shown to be a consequence of photon-plasmon collisions, taken in the geometric optics limit. A brief discussion of photon trapping by the plasma wave potential is also included. Our theoretical discussion will be illustrated with the description of recent experimental results using intense laser plasma interactions, as well as with a new experimental proposal.