Vlasov-Poisson simulation of wave-induced velocity diffusion of electrons in a collisional plasma

Jouko Berndtson, Jukka Heikkinen, Seppo Karttunen, Timo Pättikangas, Rainer Salomaa

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review


    The theory of current drive by plasma waves in tokamak plasmas relies on the quasilinear velocity diffusion of the resonant electrons against collisions. Usually, the driven current is estimated from the Fokker-Planck equation by assuming that the wave-induced diffusion can be described by the quasilinear diffusion term. In a previous paper, we investigated the validity of the quasilinear theory by one-dimensional Vlasov-Poisson simulations. For a fairly small number of large-amplitude waves, the diffusion was found to be slightly different from quasilinear. We have now included a simplified Balescu-Lenard collision term in the Vlasov-Poisson code. In the following, we investigate the formation of a steady-state current with Vlasov simulations. We compare the distribution function and the current obtained from simulations with the more conventional Fokker-Planck approach. The present simulations deal with the electron plasma waves. In the high-frequency limit, the lower hybrid waves can be approximated by magnetized electrostatic electron plasma waves. In this limit, the dispersion relation of the lower hybrid waves is approximately ω² = ωp²k||²/k², where k||²<< k², and k|| and k refer to the wave numbers parallel and perpendicular to the magnetic field, respectively. Our one-dimensional Vlasov-Poisson simulation is therefore analogous to solving the velocity distribution of the electrons in the direction parallel to the magnetic field for lower hybrid waves.
    Original languageEnglish
    Title of host publication20th EPS Conference on Controlled Fusion and Plasma Physics
    EditorsJ.A. Coasta Cabral
    Place of PublicationPetit-Lancy
    PublisherEuropean Physical Society
    Publication statusPublished - 1993
    MoE publication typeA4 Article in a conference publication
    Event20th EPS Conference on Controlled Fusion and Plasma Physics - Lissabon, Portugal
    Duration: 26 Jul 199330 Jul 1993

    Publication series

    SeriesEurophysics Conference Abstracts


    Conference20th EPS Conference on Controlled Fusion and Plasma Physics


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