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Strongly driven ion-scale turbulence in tokamak plasmas is shown to be regulated by a new propagating zonal flow mode, the toroidal secondary mode, which is nonlinearly supported by the turbulence. The mode grows and propagates due to the…

Plasma Physics · Physics 2026-03-24 Richard Nies , Felix Parra , Michael Barnes , Noah Mandell , William Dorland

In plasma wakefield accelerators, the wave excited in the plasma eventually breaks and leaves behind slowly changing fields and currents that perturb the ion density background. We study this process numerically using the example of a FACET…

Plasma Physics · Physics 2022-02-23 V. K. Khudiakov , K. V. Lotov , M. C. Downer

In partially ionized plasma, where ions can be in different ionization states, each charge state can be described as a different fluid for the purpose of multi-ion collisional transport. In the case of two charge states, transport pushes…

Plasma Physics · Physics 2022-11-23 M. E. Mlodik , E. J. Kolmes , I. E. Ochs , T. Rubin , N. J. Fisch

In a new toroidal laboratory plasma device including a poloidal magnetic field created by an internal circular conductor, the confinement efficiency of the magnetized plasma and the turbulence level are studied in different situations. The…

Plasma Physics · Physics 2015-06-11 Thiery Pierre

In tokamaks, internal transport barriers, produced by modifications of the plasma current profile, reduce particle transport and improve plasma confinement. The triggering of the internal transport barriers and their dependence on the…

Plasma Physics · Physics 2018-10-12 F. A. Marcus , M. Roberto , I. L. Caldas , K. C. Rosalem , Y. Elskens

Ion orbit loss is considered important for generating the radially inward electric field $E_r$ in a tokamak edge plasma. In particular, this effect is emphasized in diverted tokamaks with a magnetic X point. In neoclassical equilibria,…

Plasma Physics · Physics 2022-04-06 Hongxuan Zhu , T. Stoltzfus-Dueck , R. Hager , S. Ku , C. S. Chang

Sharp temperature gradients in a magnetically confined plasma can lead to turbulent motion of the plasma. This turbulence in turn enhances the transport of heat across magnetic field lines. The enhanced transport impacts the temperature…

Plasma Physics · Physics 2020-04-27 Eduardo Rodriguez , Allan H. Reiman , Nathaniel J. Fisch

The surface current on the plasma-vacuum interface during a disruption event involving kink instability can play an important role in driving current into the vacuum vessel. However, there have been disagreements over the nature or even the…

Plasma Physics · Physics 2017-10-31 C. S. Ng , A. Bhattacharjee

Plasma terminating disruptions in tokamaks may result in relativistic runaway electron beams with potentially serious consequences for future devices with large plasma currents. In this paper we investigate the effect of plasma elongation…

Compact torus injection is considered as a high promising approach to realize central fueling in the future tokamak device. Recently, a compact torus injection system has been developed for the Experimental Advanced Superconducting Tokamak,…

The role of ion polarisation and finite Larmor radius on the isotope effect on turbulent tokamak edge transport and flows is investigated by means of local electromagnetic multi-species gyro-fluid computations. Transport is found to be…

Plasma Physics · Physics 2016-11-03 Ole Hauke Heinz Meyer , Alexander Kendl

The safe operation of tokamak reactors requires a reliable modeling capability of disruptions, and in particular the spatio-temporal dynamics of associated runaway electron currents. In a disruption, instabilities can break up magnetic…

Plasma Physics · Physics 2022-09-14 István Pusztai , Mathias Hoppe , Oskar Vallhagen

Neutral atoms can strongly influence the intrinsic rotation and radial electric field at the tokamak edge. Here, we present a framework to investigate these effects when the neutrals dominate the momentum transport. We explore the parameter…

Plasma Physics · Physics 2016-10-12 John Omotani , István Pusztai , Tünde Fülöp

A first-of-its-kind experiment was conducted in the DIII-D tokamak under WEST similarity constraints on plasma shape and core parameters. This work presents a detailed transport study comparing a reference regime dominated by intrinsic…

The main populating and depopulating mechanisms of the excited energy levels of ions in plasmas with densities <1023-1024 m-3 are electron collisional excitation from the ion's ground state and radiative decay, respectively, with the…

Plasma Physics · Physics 2013-05-14 K D Lawson , I H Coffey , K M Aggarwal , F P Keenan , JET-EFDA Contributors

An investigation is made into the effect of the reduction in anomalous perpendicular electron heat transport inside the separatrix of a magnetic island chain associated with a neoclassical tearing mode in a tokamak plasma, due to the…

Plasma Physics · Physics 2017-05-24 Richard Fitzpatrick

The stochastic advection of low energy deuterium ions is studied in a three dimensional realistic turbulence model in conditions relevant for current tokamak fusion experiments. The diffusion coefficients are calculated starting from the…

Plasma Physics · Physics 2017-07-28 A. Croitoru

Flux-surface-averaged momentum loss and parallel rotation of the bulk ions at the edge of a tokamak plasma due to the ion orbit loss are calculated by computing the minimum loss energy of both the trapped and the passing thermal ions. The…

Plasma Physics · Physics 2015-06-19 Chengkang Pan , Shaojie Wang , Jing Ou

The tearing mode instability and the associated magnetic islands can lead to a degradation of tokamak plasma performance and eventually to a disruption. A crucial issue for the extension of advanced tokamak scenarios to long pulse operation…

Plasma Physics · Physics 2007-05-23 Fatemeh Hajakbari , Alireza Hojabri

Magnetically confined plasmas are often subject to relaxation oscillations accompanied by large transport events. This is particularly the case for the high confinement regime of tokamaks where these events are termed edge localized modes…