Eur. Phys. J. D (2014) 68: 79
https://doi.org/10.1140/epjd/e2014-50035-5

Regular Article

Vlasov equation for photons and quasi-particles in a plasma^*

IPFN, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal

^a e-mail: titomend@ist.utl.pt

Received: 13 January 2014
Received in final form: 12 February 2014
Published online: 15 April 2014

Abstract

We show that, in quite general conditions, a Vlasov equation can be derived for photons in a medium. The same is true for other quasi-particles, such as plasmons, phonons or driftons, associated with other wave modes in a plasma. The range of validity of this equation is discussed. We also discuss the Landau resonance, and its relation with photon acceleration. Exact and approximate expressions for photon and quasi-particle Landau damping are stated. Photon and quasi-particle acceleration and trapping is also discussed. Specific applications to laser-plasma interaction, and to magnetic fusion turbulence, are considered as illustrations of the general approach.