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Title: Interaction of a magnetic island chain in a tokamak plasma with a resonant magnetic perturbation of rapidly oscillating phase

Abstract

An investigation is made here into the interaction of a magnetic island chain, embedded in a tokamak plasma, with an externally generated magnetic perturbation of the same helicity whose helical phase is rapidly oscillating. The analysis is similar in form to the classic analysis used by Kapitza [Sov. Phys. JETP 21, 588 (1951)] to examine the angular motion of a rigid pendulum whose pivot point undergoes rapid vertical oscillations. The phase oscillations are found to modify the existing terms, and also to give rise to new terms, in the equations governing the secular evolution of the island chain's radial width and helical phase. An examination of the properties of the new secular evolution equation reveals that it is possible to phase-lock an island chain to an external magnetic perturbation with an oscillating helical phase in a stabilizing phase relation provided that the amplitude, ϵ, of the phase oscillations (in radians) is such that | J 0 ( ϵ ) | << 1 , and the mean angular frequency of the perturbation closely matches the natural angular frequency of the island chain.

Authors:
ORCiD logo [1]
  1. Univ. of Texas, Austin, TX (United States). Dept. of Physics. Inst. for Fusion Studies
Publication Date:
Research Org.:
Univ. of Texas, Austin, TX (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
OSTI Identifier:
1523375
Alternate Identifier(s):
OSTI ID: 1412619
Grant/Contract Number:  
FG02-04ER54742
Resource Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 12; 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

Citation Formats

Fitzpatrick, Richard. Interaction of a magnetic island chain in a tokamak plasma with a resonant magnetic perturbation of rapidly oscillating phase. United States: N. p., 2017. Web. doi:10.1063/1.5000253.
Fitzpatrick, Richard. Interaction of a magnetic island chain in a tokamak plasma with a resonant magnetic perturbation of rapidly oscillating phase. United States. doi:10.1063/1.5000253.
Fitzpatrick, Richard. Mon . "Interaction of a magnetic island chain in a tokamak plasma with a resonant magnetic perturbation of rapidly oscillating phase". United States. doi:10.1063/1.5000253. https://www.osti.gov/servlets/purl/1523375.
@article{osti_1523375,
title = {Interaction of a magnetic island chain in a tokamak plasma with a resonant magnetic perturbation of rapidly oscillating phase},
author = {Fitzpatrick, Richard},
abstractNote = {An investigation is made here into the interaction of a magnetic island chain, embedded in a tokamak plasma, with an externally generated magnetic perturbation of the same helicity whose helical phase is rapidly oscillating. The analysis is similar in form to the classic analysis used by Kapitza [Sov. Phys. JETP 21, 588 (1951)] to examine the angular motion of a rigid pendulum whose pivot point undergoes rapid vertical oscillations. The phase oscillations are found to modify the existing terms, and also to give rise to new terms, in the equations governing the secular evolution of the island chain's radial width and helical phase. An examination of the properties of the new secular evolution equation reveals that it is possible to phase-lock an island chain to an external magnetic perturbation with an oscillating helical phase in a stabilizing phase relation provided that the amplitude, ϵ, of the phase oscillations (in radians) is such that |J0(ϵ)|<<1, and the mean angular frequency of the perturbation closely matches the natural angular frequency of the island chain.},
doi = {10.1063/1.5000253},
journal = {Physics of Plasmas},
number = 12,
volume = 24,
place = {United States},
year = {2017},
month = {12}
}

Journal Article:
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