Results 21 to 30 of about 1,247 (174)

Revisiting the improved core confinement simulations for FT‐2 tokamak

Contributions to Plasma Physics, Volume 62, Issue 5-6, June‐July 2022., 2022
Abstract In the present paper, we revisit observations performed in FT‐2 tokamak from previous works. Improvements of core confinement are observed and believed to be caused by wide orbits going from collisionless to collisional regimes. Similar phenomena can occur whenever gradient lengths are comparable to the orbit widths at the top of the pedestal ...
Riccardo Nicolò Iorio, Laurent Chône, Evgeniy Gusakov, Timo P. Kiviniemi, Serguey Lashkul, Susan Leerink   +5 more
wiley   +1 more source

Effect of toroidal particle sources on SOL physics in the FT‐2 tokamak

Contributions to Plasma Physics, Volume 62, Issue 5-6, June‐July 2022., 2022
Abstract Two gas‐puffs are used near limiters in the FT‐2 tokamak for the purpose of hydrogen refuelling during plasma discharges. This creates toroidal and poloidal asymmetry in particle sources near limiters which has to be considered in modelling. Here, the effect of toroidal asymmetry is simulated using the gyrokinetic code ELMFIRE.
Francis Clinton Prasanth Albert Devasagayam, Laurent Chôné, Timo Petteri Kiviniemi, Oksana Kaledina, Sergei Shatalin, Alexey Dmitrievich Gurchenko, Alexey Altukhov, Evgeniy Gusakov, Mikhail Kantor, Denis Kouprienko, Sergei Lashkul   +10 more
wiley   +1 more source

An Energy Conserving Vlasov Solver That Tolerates Coarse Velocity Space Resolutions: Simulation of MMS Reconnection Events

Journal of Geophysical Research: Space Physics, Volume 127, Issue 2, February 2022., 2022
Abstract Vlasov solvers that operate on a phase‐space grid are highly accurate but also numerically demanding. Coarse velocity space resolutions, which are largely unproblematic in particle‐in‐cell (PIC) simulations, can lead to numerical heating or oscillations in continuum Vlasov methods.
F. Allmann‐Rahn, S. Lautenbach, R. Grauer   +2 more
wiley   +1 more source

Van Allen Probes Observations of Symmetric Stormtime Compressional ULF Waves

Journal of Geophysical Research: Space Physics, Volume 127, Issue 2, February 2022., 2022
Abstract Previous spacecraft studies showed that stormtime poloidal ultralow‐frequency (ULF) waves in the ring current region have an antisymmetric (second harmonic) mode structure about the magnetic equator. This paper reports Van Allen Probes observations of symmetric ULF waves in the postnoon sector during a moderate geomagnetic storm.
Kazue Takahashi, Chris Crabtree, A. Y. Ukhorskiy, Alexander Boyd, Richard E. Denton, Drew Turner, Matina Gkioulidou, Massimo Vellante, Harlan E. Spence   +8 more
wiley   +1 more source

Inertial-range kinetic turbulence in pressure-anisotropic astrophysical plasmas [PDF]

, 2015
A theoretical framework for low-frequency electromagnetic (drift-)kinetic turbulence in a collisionless, multi-species plasma is presented. The result generalises reduced magnetohydrodynamics (RMHD) and kinetic RMHD (Schekochihin et al.
Abel, IG, Chen, CHK, Cowley, SC, Kunz, MW, Schekochihin, AA   +4 more
core   +2 more sources

Theory and modeling of electron fishbones

New Journal of Physics, 2016
Internal kink instabilities exhibiting fishbone like behavior have been observed in a variety of experiments where a high energy electron population, generated by strong auxiliary heating and/or current drive systems, was present. After briefly reviewing
G Vlad, V Fusco, S Briguglio, G Fogaccia, F Zonca, X Wang   +5 more
doaj   +1 more source

Collisionless energy transfer in kinetic turbulence: field-particle correlations in Fourier space [PDF]

, 2019
Turbulence is ubiquitously observed in nearly collisionless heliospheric plasmas, including the solar wind and corona and the Earth's magnetosphere.
Howes, Gregory G., Klein, Kristopher G., Li, Tak Chu, Liu, Yi-Hsin, TenBarge, Jason M.   +4 more
core   +2 more sources

Chaotic motion of charged particles in toroidal magnetic configurations [PDF]

, 2014
We study the motion of a charged particle in a tokamak magnetic field and discuss its chaotic nature. Contrary to most of recent studies, we do not make any assumption on any constant of the motion and solve numerically the cyclotron gyration using ...
Arnold V., Benjamin Cambon, Bogoliubov N. N., Michel Vittot, Neishtadt A. I., Rémi Dumont, Xavier Garbet, Xavier Leoncini, Yushmanov P. N.   +8 more
core   +4 more sources

Practical gyrokinetics [PDF]

Journal of Plasma Physics, 2019
Thousands of gyrokinetic papers have been published since the introduction of the gyrokinetic change of variables. The intent here is not to review the field, but rather the goal is to present a tutorial providing insight into why gyrokinetics is an appropriate description of turbulent transport.
openaire   +1 more source

Collisional gyrokinetic full‐f particle‐in‐cell simulations on open field lines with PICLS

Contributions to Plasma Physics, Volume 60, Issue 5-6, June-July 2020., 2020
Abstract Applying gyrokinetic simulations in theoretical turbulence and transport studies for the plasma edge and scrape‐off layer (SOL) presents significant challenges. To particularly account for steep density and temperature gradients in the SOL, the “full‐f” code PICLS was developed.
Mathias Boesl, Andreas Bergmann, Alberto Bottino, Stephan Brunner, David Coster, Frank Jenko   +5 more
wiley   +1 more source