Twofluid tearing mode instability in cylindrical geometry
 Authors:
 National Institute for Fusion Science, National Institutes of Natural Sciences, 3226 Oroshicho, Toki 5095292, Japan
 Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 021394307, USA
 Publication Date:
 Sponsoring Org.:
 USDOE
 OSTI Identifier:
 1366569
 Grant/Contract Number:
 DEFG0291ER54109, DEFC0208ER54969
 Resource Type:
 Journal Article: Publisher's Accepted Manuscript
 Journal Name:
 Physics of Plasmas
 Additional Journal Information:
 Journal Volume: 24; Journal Issue: 7; Related Information: CHORUS Timestamp: 20180215 00:20:17; Journal ID: ISSN 1070664X
 Publisher:
 American Institute of Physics
 Country of Publication:
 United States
 Language:
 English
Citation Formats
Ito, Atsushi, and Ramos, Jesús J. Twofluid tearing mode instability in cylindrical geometry. United States: N. p., 2017.
Web. doi:10.1063/1.4986116.
Ito, Atsushi, & Ramos, Jesús J. Twofluid tearing mode instability in cylindrical geometry. United States. doi:10.1063/1.4986116.
Ito, Atsushi, and Ramos, Jesús J. 2017.
"Twofluid tearing mode instability in cylindrical geometry". United States.
doi:10.1063/1.4986116.
@article{osti_1366569,
title = {Twofluid tearing mode instability in cylindrical geometry},
author = {Ito, Atsushi and Ramos, Jesús J.},
abstractNote = {},
doi = {10.1063/1.4986116},
journal = {Physics of Plasmas},
number = 7,
volume = 24,
place = {United States},
year = 2017,
month = 7
}
Free Publicly Available Full Text
This content will become publicly available on June 27, 2018
Publisher's Accepted Manuscript
DOI: 10.1063/1.4986116
Other availability
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

Nonlinear asymmetric tearing mode evolution in cylindrical geometry
The growth of a tearing mode is described by reduced MHD equations. For a cylindrical equilibrium, tearing mode growth is governed by the modified Rutherford equation, i.e., the nonlinear Δ'(w). For a low beta plasma without external heating, Δ'(w) can be approximately described by two terms, Δ' _{ql}(w), Δ'A(w). In this work, we present a simple method to calculate the quasilinear stability index Δ'ql rigorously, for poloidal mode number m ≥ 2. Δ' _{ql} is derived by solving the outer equation through the Frobenius method. Δ'ql is composed of four terms proportional to: constant Δ' _{0}, w, wlnw, and w2.more » 
Rigorous approach to the nonlinear saturation of the tearing mode in cylindrical and slab geometry
The saturation of the tearing mode instability is described within the standard framework of reduced magnetohydrodynamics in the case of an rdependent or uniform resistivity profile. Using the technique of matched asymptotic expansions, where the perturbation parameter is the island width w, the problem can be solved in two ways: with the socalled flux coordinate method, which is based on the fact that the current profile is a flux function, and with a new perturbative method that does not use this property. The latter is applicable to more general situations where an external forcing or a sheared velocity profile aremore » 
Effect of sheared equilibrium plasma rotation on the classical tearing mode in a cylindrical geometry
The effect of sheared equilibrium plasma rotation on the stability of tearing modes in an Ohmic (low plasma {beta}) regime is investigated. It is found, by means of numerical MHD simulations in a cylindrical geometry, that plasma rotation in the equivalent toroidal direction can result either in the increase or in the decrease of the instability growth rate. Perpendicular plasma viscosity and plasma rotation shear at the modes' rational surface play a key role on assessing the effect of shear flow. While destabilizing for low viscosity plasmas (ratio of the resistive to viscous diffusion time scales {tau}{sub R}/{tau}{sub V}<<1), formore » 
Tearingmode instability in cylindrical plasma configurations
The effect of cylindrical neutral sheet geometry on the tearingmode (disruptive) instability is studied in detail. The instability growth rates are found for all the pertinent cases. Cylindrical effects come into play when the distance from the neutral sheet to the axis is small in comparison with the characteristic thickness of the sheet. The ultimate result is that the electron instability mode is replaced by an ion mode. These results are of interest in connection with the study of the plasma stability in devices of the Astron type and in magnetospheres like that of Uranus.