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Title: Parameter-Space Survey of Linear G-mode and Interchange in Extended Magnetohydrodynamics

Abstract

The extended magnetohydrodynamic stability of interchange modes is studied in two configurations. In slab geometry, a local dispersion relation for the gravitational interchange mode (g-mode) with three different extensions of the MHD model [P. Zhu, et al., Phys. Rev. Lett. 101, 085005 (2008)] is analyzed. Our results delineate where drifts stablize the g-mode with gyroviscosity alone and with a two-fluid Ohm’s law alone. Including the two-fluid Ohm’s law produces an ion drift wave that interacts with the g-mode. This interaction then gives rise to a second instability at finite k y. A second instability is also observed in numerical extended MHD computations of linear interchange in cylindrical screw-pinch equilibria, the second configuration. Particularly with incomplete models, this mode limits the regions of stability for physically realistic conditions. But, applying a consistent two-temperature extended MHD model that includes the diamagnetic heat flux density ($$\vec{q}$$ *) makes the onset of the second mode occur at larger Hall parameter. For conditions relevant to the SSPX experiment [E.B. Hooper, Plasma Phys. Controlled Fusion 54, 113001 (2012)], significant stabilization is observed for Suydam parameters as large as unity (D s≲1).

Authors:
 [1];  [1]
  1. Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics
Publication Date:
Research Org.:
Univ. of Wisconsin, Madison, WI (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
OSTI Identifier:
1390175
Alternate Identifier(s):
OSTI ID: 1395917; OSTI ID: 1436977
Report Number(s):
UW-CPTC 17-5
Journal ID: ISSN 1070-664X
Grant/Contract Number:
FG02-06ER54850; FC02-05ER54813; FC02-08ER54975
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 10; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; mathematical foundations: fluid and multi-fluid theory; instabilities: hydromagnetic; computer simulation: MHD

Citation Formats

Howell, E. C., and Sovinec, C. R. Parameter-Space Survey of Linear G-mode and Interchange in Extended Magnetohydrodynamics. United States: N. p., 2017. Web. doi:10.1063/1.4993440.
Howell, E. C., & Sovinec, C. R. Parameter-Space Survey of Linear G-mode and Interchange in Extended Magnetohydrodynamics. United States. doi:10.1063/1.4993440.
Howell, E. C., and Sovinec, C. R. Mon . "Parameter-Space Survey of Linear G-mode and Interchange in Extended Magnetohydrodynamics". United States. doi:10.1063/1.4993440.
@article{osti_1390175,
title = {Parameter-Space Survey of Linear G-mode and Interchange in Extended Magnetohydrodynamics},
author = {Howell, E. C. and Sovinec, C. R.},
abstractNote = {The extended magnetohydrodynamic stability of interchange modes is studied in two configurations. In slab geometry, a local dispersion relation for the gravitational interchange mode (g-mode) with three different extensions of the MHD model [P. Zhu, et al., Phys. Rev. Lett. 101, 085005 (2008)] is analyzed. Our results delineate where drifts stablize the g-mode with gyroviscosity alone and with a two-fluid Ohm’s law alone. Including the two-fluid Ohm’s law produces an ion drift wave that interacts with the g-mode. This interaction then gives rise to a second instability at finite ky. A second instability is also observed in numerical extended MHD computations of linear interchange in cylindrical screw-pinch equilibria, the second configuration. Particularly with incomplete models, this mode limits the regions of stability for physically realistic conditions. But, applying a consistent two-temperature extended MHD model that includes the diamagnetic heat flux density ($\vec{q}$*) makes the onset of the second mode occur at larger Hall parameter. For conditions relevant to the SSPX experiment [E.B. Hooper, Plasma Phys. Controlled Fusion 54, 113001 (2012)], significant stabilization is observed for Suydam parameters as large as unity (Ds≲1).},
doi = {10.1063/1.4993440},
journal = {Physics of Plasmas},
number = 10,
volume = 24,
place = {United States},
year = {Mon Sep 11 00:00:00 EDT 2017},
month = {Mon Sep 11 00:00:00 EDT 2017}
}

Journal Article:
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