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Title: Robustness and Flexibility in NCSX: Global Ideal MHD Stability and Energetic Particle Transport

Abstract

Concerns about the flexibility and robustness of a compact quasiaxial stellarator design are addressed by studying the effects of varied pressure and iota profiles. For thirty related equilibrium configurations the global, ideal magnetohydrodynamic (MHD) stability is evaluated as well as energetic particle transport. It is found that tokamak intuition is useful to understanding the MHD stability, with pressure gradient driving terms and shear stabilization controlling both the N=0 and N=1 unstable modes. Global kink modes are generated by steeply peaked profiles and edge localized modes are found for plasmas with edge iota above 0.5. Energetic particle transport is not strongly dependent on these changes of pressure and iota profiles, although a weak inverse dependence on pressure peaking through the magnetic axis Shafranov shift is found. While good transport and MHD stability are not anticorrelated in these 30 equilibria, stability depends on a delicate balance of the pressure and shear stabilization forces.

Authors:
; ; ; ;  [1]
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  1. and others
Publication Date:
Research Org.:
Princeton Plasma Physics Lab., NJ (US)
Sponsoring Org.:
USDOE Office of Energy Research (ER) (US)
OSTI Identifier:
12542
Report Number(s):
PPPL-3358
AC02-CHO-3073; TRN: US0102554
DOE Contract Number:
AC02-76CH03073
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 7 Oct 1999
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; DESIGN; EDGE LOCALIZED MODES; FLEXIBILITY; MAGNETOHYDRODYNAMICS; STABILIZATION; STELLARATORS; BEAM TRANSPORT; PARTICLE BEAMS; KINK INSTABILITY

Citation Formats

A. Diallo, G.Y. Fu, J.L. Johnson, M.H. Redi, and W.A. Cooper. Robustness and Flexibility in NCSX: Global Ideal MHD Stability and Energetic Particle Transport. United States: N. p., 1999. Web. doi:10.2172/12542.
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A. Diallo, G.Y. Fu, J.L. Johnson, M.H. Redi, & W.A. Cooper. Robustness and Flexibility in NCSX: Global Ideal MHD Stability and Energetic Particle Transport. United States. doi:10.2172/12542.
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A. Diallo, G.Y. Fu, J.L. Johnson, M.H. Redi, and W.A. Cooper. Thu . "Robustness and Flexibility in NCSX: Global Ideal MHD Stability and Energetic Particle Transport". United States. doi:10.2172/12542. https://www.osti.gov/servlets/purl/12542.
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@article{osti_12542,
title = {Robustness and Flexibility in NCSX: Global Ideal MHD Stability and Energetic Particle Transport},
author = {A. Diallo and G.Y. Fu and J.L. Johnson and M.H. Redi and W.A. Cooper},
abstractNote = {Concerns about the flexibility and robustness of a compact quasiaxial stellarator design are addressed by studying the effects of varied pressure and iota profiles. For thirty related equilibrium configurations the global, ideal magnetohydrodynamic (MHD) stability is evaluated as well as energetic particle transport. It is found that tokamak intuition is useful to understanding the MHD stability, with pressure gradient driving terms and shear stabilization controlling both the N=0 and N=1 unstable modes. Global kink modes are generated by steeply peaked profiles and edge localized modes are found for plasmas with edge iota above 0.5. Energetic particle transport is not strongly dependent on these changes of pressure and iota profiles, although a weak inverse dependence on pressure peaking through the magnetic axis Shafranov shift is found. While good transport and MHD stability are not anticorrelated in these 30 equilibria, stability depends on a delicate balance of the pressure and shear stabilization forces.},
doi = {10.2172/12542},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Oct 07 00:00:00 EDT 1999},
month = {Thu Oct 07 00:00:00 EDT 1999}
}
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Technical Report:
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DOI:  10.2172/12542
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