caa a22 4500 386367930 CHVBK 20180307111943.0 cr unu---uuuuu 161130e198906 xx s 000 0 eng 10.1017/S0022377800014045 doi S0022377800014045 pii (NATIONALLICENCE)cambridge-10.1017/S0022377800014045 Large-Debye-distance effects in a homogeneous plasma [Elektronische Daten] The classical phenomenon of electron plasma oscillations has been investigated from new aspects. The applicability of standard normal-mode analysis of plasma perturbations has been judged from comparisons with exact numerical solutions to the linearized initial-value problem. We consider both Maxwellian and non-Maxwellian velocity distributions. Emphasis is on perturbations for which αλD is of order unity, where α is the wavenumber and λD the Debye distance. The corresponding large-Debye-distance (LDD) damping is found to substantially dominate over Landau damping. This limits the applicability of normal-mode analysis of non-Maxwellian distributions. The physics of LDD damping and its close connection to large-Larmor-radius (LLR) damping is discussed. A major discovery concerns perturbations of plasmas with non-Maxwellian, bump-in-tail, velocity distribution functions f0(ω). For sufficiently large αλD (of order unity) the plasma responds by damping perturbations that are initially unstable in the Landau sense, i.e. with phase velocities initially in the interval where df0/dw > 0. It is found that the plasma responds through shifting the phase velocity above the upper velocity limit of this interval. This is shown to be due to a resonance with the drifting electrons of the bump, and explains the Penrose criterion. Copyright © Cambridge University Press 1989 Scheffel Jan The Royal Institute of Technology, S-100 44 Stockholm, Sweden Lehnert Bo The Royal Institute of Technology, S-100 44 Stockholm, Sweden Journal of Plasma Physics Cambridge University Press 41/3(1989-06), 493-516 0022-3778 41:3<493 1989 41 PLA https://doi.org/10.1017/S0022377800014045 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0022377800014045 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Scheffel Jan The Royal Institute of Technology, S-100 44 Stockholm, Sweden NATIONALLICENCE 700 1- Lehnert Bo The Royal Institute of Technology, S-100 44 Stockholm, Sweden NATIONALLICENCE 773 0- Journal of Plasma Physics Cambridge University Press 41/3(1989-06), 493-516 0022-3778 41:3<493 1989 41 PLA CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge