In:
Journal of Plasma Physics, Cambridge University Press (CUP), Vol. 59, No. 1 ( 1998-01), p. 103-123
Abstract:
The nonlinear dynamics and structure of plasmas with
tightly twisted magnetic field lines have been studied using a toroidal plasma device. Stepwise
magnetohydrodynamic (MHD) relaxation occurs, resulting in a discontinuous change in the pitch of magnetic field lines. This discrete
nature of the pitch stems from the instability of kink (torsional) modes. The MHD relaxation
stabilizes kink modes by selecting (self-organizing) appropriate pitches. The self-organized state displays the characteristic of a
‘dissipative structure’ in that it is accompanied by enhanced energy dissipation; the global
resistance of the plasma current is substantially enhanced. The magnetic energy, which is
generated by the internal plasma current, first changes into fluctuation energy
through the kink instability, and then it goes mainly to ion thermal energy through viscous dissipation of the fluctuating flow. The
viscosity dissipates the fluctuation energy with conservation of helicity. The self-organization
of the stabilized magnetic field is characterized by the preferential conservation of the helicity.
Type of Medium:
Online Resource
ISSN:
0022-3778
,
1469-7807
DOI:
10.1017/S002237789700617X
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
1998
detail.hit.zdb_id:
2004297-8
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