TSVV-G meeting (MHD: XTOR etc)

Europe/Berlin
    • 14:00 14:45
      Status of XTOR-K 45m
      Speakers: Guillaume Brochard (CEA), Hinrich Lutjens (CEA)
    • 14:45 15:30
      Comparisons between XTOR and JOREK. Van-Kampen model and recent results with VENUS-KMHD. Plans for the code. 45m

      Links to a series of papers, discussing the difference between the Van Kampen and Landau spectra and how they match when adding dissipation. In particular, the collisionless Landau spectrum is recovered by the Van Kampen spectra when adding some form of dissipation (physical collisions or hyperdiffusion) and taking the limit of dissipation going to zero. Key in understanding these results is realizing that adding dissipation is a singular perturbation, so that taking the limit dissipation->0 is not equivalent as dissipation=0.

      Papers by Ng, Bhattacharjee, Skiff:
      https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.83.1974

      https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.92.065002

      Paper & thesis by Bratanov
      https://pubs.aip.org/aip/pop/article/20/2/022108/107223/Aspects-of-linear-Landau-damping-in-discretized
      https://www.theorie.physik.uni-muenchen.de/TMP/theses/thesis_bratanov.pdf

      Original paper by VanKampen, reconciling the apparent paradox between undamped singular VanKampen modes and smooth (collisionless) damped Landau modes:
      https://www.sciencedirect.com/science/article/pii/S0031891455930688

      Speakers: Hugo Jean Elie Chkroun (EPFL), Jeanquartier Fabien Nicolas (EPFL), Jonathan Graves (EPFL), Marcus Quantril (University of York), Stephan Brunner (EPFL)
      Links to a series of papers, discussing the difference between the Van Kampen and Landau spectra and how they match when adding dissipation. In particular, the collisionless Landau spectrum is recovered by the Van Kampen spectra when adding some form of dissipation (physical collisions or hyperdiffusion) and taking the limit of dissipation going to zero. Key in understanding these results is realizing that adding dissipation is a singular perturbation, so that taking the limit dissipation->0 is not equivalent as dissipation=0.
       
      Papers by Ng, Bhattacharjee, Skiff:
       
      Paper & thesis by Bratanov
       
      Original paper by VanKampen, reconciling the apparent paradox between undamped singular VanKampen modes and smooth (collisionless) damped Landau modes: