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The key basis for tokamak plasma disruption modeling is to understand how currents flow to the plasma facing surfaces during plasma disruption events. In ITER tokamak, the occurrence of a limited number of major disruptions will…

Plasma Physics · Physics 2022-01-26 Cǎlin V. Atanasiu , Leonid E. Zakharov , Karl Lackner , Matthias Hoelzl

Advanced tokamak scenarios often feature equilibriums with zero and reversed magnetic shear. To isolate and investigate their impacts on the resistive wall mode (RWM) instability analytically, we construct a series of cylindrical limiter…

Plasma Physics · Physics 2024-01-12 Sui Wan , Ping Zhu , Haolong Li , Rui Han

An innovative millimeter wave diagnostic is proposed to measure the local magnetic field and edge current as a function of the minor radius in the tokamak pedestal region. The idea is to identify the direction of minimum reflectivity at the…

Plasma Physics · Physics 2016-09-21 O. Meneghini , F. A. Volpe

We study the free boundary problem for a plasma-vacuum interface in ideal incompressible magnetohydrodynamics. Unlike the classical statement when the vacuum magnetic field obeys the div-curl system of pre-Maxwell dynamics, to better…

Analysis of PDEs · Mathematics 2020-07-15 Alessandro Morando , Paolo Secchi , Yuri Trakhinin , Paola Trebeschi

A mechanism for fast magnetic reconnection in collisionless plasma is studied for understanding sawtooth collapse in tokamak discharges by using a two-fluid model for cold ions and electrons. Explosive growth of the tearing mode enabled by…

Plasma Physics · Physics 2015-06-12 M. Hirota , P. J. Morrison , Y. Ishii , M. Yagi , N. Aiba

The competition between the drive and stabilization of plasma microinstabilities by sheared flow is investigated, focusing on the ion temperature gradient mode. Using a twisting mode representation in sheared slab geometry, the…

Plasma Physics · Physics 2015-05-19 Sarah L. Newton , Steve C. Cowley , Nuno F. Loureiro

The real-time reconstruction of the plasma magnetic equilibrium in a Tokamak is a key point to access high performance regimes. Indeed, the shape of the plasma current density profile is a direct output of the reconstruction and has a…

Numerical Analysis · Mathematics 2016-11-27 Didier Mazon , Jacques Blum , Cédric Boulbe , Blaise Faugeras , A. Boboc , M. Brix , P. De Vries , S. Sharapov , L. Zabeo

We have carried out high resolution MHD simulations of the nonlinear evolution of Kelvin-Helmholtz unstable flows in 2 1/2 dimensions. The modeled flows and fields were initially uniform except for a thin shear layer with a hyperbolic…

Astrophysics · Physics 2009-10-30 T. W. Jones , Joseph B. Gaalaas , Dongsu Ryu , Adam Frank

In this paper we study a simple model consisting of a dilute fully ionized plasma in the presence of the gravitational and a constant magnetic field to analyze the propagation of hydromagnetic instabilities. In particular we show that the…

Astrophysics · Physics 2007-05-23 A. Sandoval-Villalbazo , L. S. Garcia-Colin , A. Arrieta

A highly elongated plasma is desirable in order to increase plasma pressure and energy confinement to maximize fusion power output. However, there is a limit to the maximum achievable elongation which is set by vertical instabilities driven…

Plasma Physics · Physics 2017-05-24 Jungpyo Lee , Jeffrey P. Freidberg , Antoine J. Cerfon , Martin Greenwald

A self-consistent nonlinear hydrodynamic theory is presented of the propagation of a long and thin relativistic electron beam through a plasma that is relatively strongly magnetized, $|\Omega_e|\sim\omega_{pe}$ and whose density is much…

Plasma Physics · Physics 2018-07-04 Dusan Jovanovic , Renato Fedele , Milivoj Belic , Sergio De Nicola

This paper deals with the numerical reconstruction of the plasma current density in a Tokamak and of its equilibrium. The problem consists in the identification of a non-linear source in the 2D Grad-Shafranov equation, which governs the…

Numerical Analysis · Mathematics 2009-11-26 Jacques Blum , Cédric Boulbe , Blaise Faugeras

We analyze the stability of a dilute plasma with thermal and composition gradients in the limit where conduction is slow compared to the dynamical timescale. We find necessary and sufficient conditions for stability when the background…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-16 Martin E. Pessah , Sagar Chakraborty

In this paper, we develop the analysis of a two-dimensional magnetohydrodynamical configuration for an axially symmetric and rotating plasma (embedded in a dipole like magnetic field), modeling the structure of a thin accretion disk around…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Giovanni Montani , Riccardo Benini

Plasma rotation in connection to both zonal and mean (equilibrium) flows can play a role in the transitions to the advanced confinement regimes in tokamaks, as the L-H transition and the formation of Internal Transport Barriers. For…

Plasma Physics · Physics 2016-08-24 George Poulipoulis , George N. Throumoulopoulos , Christian Konz

The effect of magnetic shear and shear flow on local gravitationally induced instabilities is investigated. A simple model is constructed allowing for an arbitrary entropy gradient and a shear plasma flow in the Boussinesq approximation. A…

Astrophysics · Physics 2009-11-06 Gregory G. Howes , Steven C. Cowley , James C. McWilliams

We examine the linear stability of an isothermal filamentary cloud permeated by a perpendicular magnetic field. Our model cloud is assumed to be supported by gas pressure against the self-gravity in the unperturbed state. For simplicity,…

Astrophysics of Galaxies · Physics 2017-10-11 Tomoyuki Hanawa , Takahiro Kudoh , Kohji Tomisaka

We study the evolution of magnetohydrodynamic turbulence taking into account the chiral anomaly effect. This chiral magnetohydrodynamic description of the plasma is expected to be relevant for temperatures comparable to the electroweak…

High Energy Physics - Theory · Physics 2021-02-23 Petar Pavlović , Günter Sigl

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

We study the stability of particles in slip-stacking configuration, used to nearly double proton beam intensity at Fermilab. We introduce universal area factors to calculate the available phase space area for any set of beam parameters…

Accelerator Physics · Physics 2015-06-22 Jeffrey Eldred , Robert Zwaska