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High-resolution magnetohydrodynamic equilibrium code for unity beta plasmas

P.-A. Gourdain, J.-N. Leboeuf, R.Y. Neches
2006 Journal of Computational Physics  
However, few equilibrium codes maintain solid numerical behavior as beta approaches unity.  ...  There is great interest in the properties of extremely high-beta magnetohydrodynamic equilibria in axisymmetric toroidal geometry and the stability of such equilibria.  ...  Guazzotto for running the FLOW code to compare the results with CUBE in a high β mode. The authors are also grateful to S. C. Cowley for his help on high β.  ... 
doi:10.1016/j.jcp.2005.12.005 fatcat:neg4a7b3ojbexo6xzzfqihakze

Dual equilibrium in a finite aspect ratio tokamak

P.-A. Gourdain, J.-N. Leboeuf
2008 Physics Letters A  
A new approach to high pressure magnetically-confined plasmas is necessary to design efficient fusion devices.  ...  This paper presents an equilibrium combining two solutions of the Grad-Shafranov equation, which describes the magnetohydrodynamic equilibrium in toroidal geometry.  ...  Steve Cowley for his constant support in unity beta research, as well as Dr. Alan Glasser from Los Alamos National Laboratory and Drs.  ... 
doi:10.1016/j.physleta.2008.08.004 fatcat:37ld4snlk5hxbks4obrqhff3mu

Magnetic Reconnection Triggering Magnetohydrodynamic Instabilities during a Sawtooth Crash in a Tokamak Plasma

I. T. Chapman, R. Scannell, W. A. Cooper, J. P. Graves, R. J. Hastie, G. Naylor, A. Zocco
2010 Physical Review Letters  
Thomson scattering measurements with subcentimeter spatial resolution have been made during a sawtooth crash in a Mega Ampere Spherical Tokamak fusion plasma.  ...  The increased local temperature gradient is sufficient to make the helical core unstable to ideal magnetohydrodynamic instabilities, thought to be responsible for the rapidity of the collapse.  ...  A more accurate nonaxisymmetric stability analysis of the kinked equilibrium has been undertaken by using the VMEC 3D equilibrium code [22] and the TERPSICHORE 3D linear stability code [23] .  ... 
doi:10.1103/physrevlett.105.255002 pmid:21231596 fatcat:3yziqzg6k5ezzpidcjafx4ybzq

Macroscopic stability of high β MAST plasmas

I.T. Chapman, W.A. Cooper, J.P. Graves, M.P. Gryaznevich, R.J. Hastie, T.C. Hender, D.F. Howell, M.-D. Hua, G.T.A. Huysmans, D.L. Keeling, Y.Q. Liu, H.F. Meyer (+4 others)
2011 Nuclear Fusion  
High resolution Charge Exchange Recombination Spectroscopy (CXRS) provided measurement of rotation braking induced by both applied magnetic fields and by magnetohydrodynamic (MHD) instabilities, allowing  ...  instabilities in high performance plasmas.  ...  The current profile and plasma shape are then supplied to the Helena equilibrium code [24] together with the pressure profile shape derived from the high resolution Thomson scattering measurements of  ... 
doi:10.1088/0029-5515/51/7/073040 fatcat:wbdrcc7z3vb7rnvfl5sts3bv7q

Toward detailed prominence seismology

J. W. S. Blokland, R. Keppens
2011 Astronomy and Astrophysics  
The code is then used to construct more realistic prominence equilibria, for all three possible choices of a free flux-function.  ...  Numerical equilibria are computed with a finite element-based code, demonstrating fourth order accuracy on an explicitly known, non-trivial test case. Results.  ...  The plasma beta ranges from 0.00069 in the low pressure regions up to 0.117 in the high pressure regions. For this equilibrium, we also computed the safety factor q and the Shafranov shift.  ... 
doi:10.1051/0004-6361/201117013 fatcat:rjjmsdjmjff7bfetwgezo5wcym

Nonlinear magnetohydrodynamic modeling of current-drive-induced sawtooth-like crashes in the W7-X stellarator [article]

Yao Zhou, K. Aleynikova, N. M. Ferraro
2022 arXiv   pre-print
We present a nonlinear magnetohydrodynamic simulation of this phenomenon using the newly developed stellarator modeling capability of the M3D-C^1 code.  ...  Wright for helpful discussions. YZ was sponsored by Shanghai Pujiang Program under Grant No. 21PJ1408600. NMF was supported by the U.S. Department of Energy under contract number DE-AC02-09CH11466.  ...  The United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States  ... 
arXiv:2207.08620v1 fatcat:hthxclupz5do7g7k3oefap4lpq

A method of computational magnetohydrodynamics defining stable Scyllac equilibria

O. Betancourt, P. Garabedian
1977 Proceedings of the National Academy of Sciences of the United States of America  
A computer code has been developed for the numerical calculation of sharp boundary equilibria of a toroidal plasma with diffuse pressure profile.  ...  By running the code, equi-  ...  ibria that are stable to the so-called m = 1, k = 0 mode have been found for Scyllac, which is a high beta toroidal confinement device of very large aspect ratio.  ... 
doi:10.1073/pnas.74.2.393 pmid:16592383 pmcid:PMC392293 fatcat:i6sn45jyizbl3pjky5pwix6un4

Two-dimensional magnetohydrodynamic simulations of poloidal flows in tokamaks and MHD pedestal

L. Guazzotto, R. Betti
2011 Physics of Plasmas  
According to the magnetohydrodynamic (MHD) equilibrium theory [R. J. P. Freidberg, Phys.  ...  Poloidal rotation is routinely observed in present-day tokamak experiments, in particular near the plasma edge and in the high-confinement mode of operation.  ...  Moreover, the analysis in Ref. 3 assumes a circular cross section for a high aspect ratio and low-beta plasma.  ... 
doi:10.1063/1.3640809 fatcat:5nbd52xwtjfm3lhxu7i3zzt4pa

Resistive instabilities in reversed shear discharges and wall stabilization on JT-60U

S Takeji, S Tokuda, T Fujita, T Suzuki, A Isayama, S Ide, Y Ishii, Y Kamada, Y Koide, T Matsumoto, T Oikawa, T Ozeki (+1 others)
2002 Nuclear Fusion  
Waveforms of plasma parameters in a typical high performance reversed shear discharge are shown in (a) of Fig.1 .  ...  Resistive interchange modes with n = 1 are found to appear in reversed shear discharges with large pressure gradient at the normalized beta, β N , of about unity or even lower.  ...  Ishizawa for her assistance for stability analysis using the MARG2D code.  ... 
doi:10.1088/0029-5515/42/1/302 fatcat:rxrej7ndrzaudmwgzhd7nrd23a

Resistive magnetohydrodynamic simulations of the ideal tearing mode [article]

Simone Landi, Luca Del Zanna, Emanuele Papini, Fulvia Pucci, Marco Velli
2015 arXiv   pre-print
be natural having the ideal case as a limit for S→∞.  ...  We study the linear and nonlinear evolution of the tearing instability on thin current sheets by means of two-dimensional numerical simulations, within the framework of compressible, resistive magnetohydrodynamics  ...  the asymptotic plasma beta.  ... 
arXiv:1504.07036v1 fatcat:3uqdh6jslfelfdg5remk7hpbba

Magnetic flux pumping in 3D nonlinear magnetohydrodynamic simulations

I. Krebs, S. C. Jardin, S. Günter, K. Lackner, M. Hoelzl, E. Strumberger, N. Ferraro
2017 Physics of Plasmas  
the M3D-C^1 code.  ...  It is shown that sawtoothing is prevented in the simulations if β is sufficiently high to provide the necessary drive for the (m=1,n=1) instability that generates the dynamo loop voltage.  ...  DE-AC02-09CH11466, the Max-Planck/Princeton Center for Plasma Physics, and the SciDAC Center for Extended MHD Modeling. Notice: This manuscript is based upon work supported by the U.S.  ... 
doi:10.1063/1.4990704 fatcat:6252gpw5rzchtn7cqsfrthao7y

Dynamic models of the sun from the convection zone to the chromosphere

Sven Wedemeyer-Böhm
2006 Proceedings of the International Astronomical Union  
In the middle chromosphere above an average height of 1000 km, plasma beta gets larger than one and magnetic fields become more important.  ...  The chromosphere in internetwork regions of the quiet Sun was regarded as a static and homogeneous layer for a long time.  ...  In order to make progress, the radiation magnetohydrodynamics code CO 5 BOLD (Freytag et al. 2002) has been upgraded recently.  ... 
doi:10.1017/s1743921307000105 fatcat:l4zzvtqf2zdonlcmet5zchpg5q

Saturated ideal modes in advanced tokamak regimes in MAST

I.T. Chapman, M.-D. Hua, S.D. Pinches, R.J. Akers, A.R. Field, J.P. Graves, R.J. Hastie, C.A. Michael
2010 Nuclear Fusion  
MAST plasmas with a safety factor above unity and a profile with either weakly reversed shear, or broad low shear regions, regularly exhibit long-lived saturated ideal magnetohydrodynamic (MHD) instabilities  ...  This could be of significance for advanced scenarios, or hybrid scenarios which aim to keep the safety factor just above rational surfaces associated with deleterious resistive MHD instabilities.  ...  The current profile and plasma shape are then supplied to the Helena equilibrium code [56] together with the pressure profile shape derived from the high resolution Thomson scattering measurements of  ... 
doi:10.1088/0029-5515/50/4/045007 fatcat:ulaxdebnkjapbcgtklhacqonja

INTERACTING TILT AND KINK INSTABILITIES IN REPELLING CURRENT CHANNELS

R. Keppens, O. Porth, C. Xia
2014 Astrophysical Journal  
Since oppositely directed current channels repel, the equilibrium is liable to an ideal magnetohydrodynamic tilt instability.  ...  We present a numerical study in resistive magnetohydrodynamics where the initial equilibrium configuration contains adjacent, oppositely directed, parallel current channels.  ...  Although this is certainly on the low side for actual fluxropes or coronal loop complexes, we note that one could exploit more freedom in the equilibrium setup to arrive at lower plasma beta, overdense  ... 
doi:10.1088/0004-637x/795/1/77 fatcat:ovifgs2lybgxpkkwkufjp5bx4q

On steady poloidal and toroidal flows in tokamak plasmas

K. G. McClements, M. J. Hole
2010 Physics of Plasmas  
It is pointed out that the range of poloidal flows for which the GS equation is hyperbolic increases with plasma beta and B / B, thereby complicating the problem of determining spherical tokamak plasma  ...  The effects of poloidal and toroidal flows on tokamak plasma equilibria are examined in the magnetohydrodynamic limit.  ...  This suggests that the presence of transonic poloidal flows in high performance spherical tokamak plasmas, with ␤ and B / B both of order unity, could pose serious numerical challenges for equilibrium  ... 
doi:10.1063/1.3469580 fatcat:v3y4kwpsuzeb3ol7pctoy3j25y
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