Parameter-Space Survey of Linear G-mode and Interchange in Extended Magnetohydrodynamics
- Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics
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 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. However, applying a consistent two-temperature extended MHD model that includes the diamagnetic heat flux density (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).
- Research Organization:
- Univ. of Wisconsin, Madison, WI (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Fusion Energy Sciences (FES)
- Grant/Contract Number:
- FG02-06ER54850; FC02-05ER54813; FC02-08ER54975
- OSTI ID:
- 1390175
- Alternate ID(s):
- OSTI ID: 1395917; OSTI ID: 1436977
- Report Number(s):
- UW-CPTC 17-5
- Journal Information:
- Physics of Plasmas, Vol. 24, Issue 10; ISSN 1070-664X
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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