D. A. Hartmann M.-L. Mayoral J. Heikkinen J.-M. Noterdaeme E. Righi et al.
On JET the coupling resistance averaged over the four straps of the A2 antennas in the Mark II GB divertor configuration was analyzed with particular emphasis on the plasma shape dependence. The measured values were compared with models for the coupling resistance of different levels of sophistication with the ultimate goal of supplying recipes on …
PublishedS. C. Chapman R. O. Dendy G. Rowlands
There is increasing evidence that the Earth’s magnetosphere, like other macroscopic confined plasma systems (magnetic fusion plasmas, astrophysical accretion discs), displays sandpile-type phenomenology so that energy dissipation is by means of avalanches which do not have an intrinsic scale. This may in turn imply that these systems evolve via s…
PublishedJ. W. Connor R. J. Hastie
It has been suggested [Kleva and Guzdar, Phys. Plasmas 6 , 116 (1999)] that reconnecting ballooning modes in which electron inertia replaces resistivity in a nonideal magnetohydrodynamic Ohm’s law can have substantial growth rates in the low collisionality regime. Numerical calculation, albeit necessarily at unrealistically large values of the co…
PublishedA. Bondeson C. G. Gimblett R. J. Hastie
The possibility of stabilizing ideal magnetohydrodynamical (MHD) instabilities by resistive walls and slow plasma rotation (rotation frequencies comparable to resistive tearing growth rates) was proposed recently by Finn [Phys. Plasmas 2 , 3782 (1995)] on the basis of cylindrical theory. In the present paper we analyze toroidal effects (pressure gr…
PublishedH. R. Wilson R. L. Miller
The peeling mode restricts access to the second stability region of the ideal ballooning mode at the tokamak plasma edge. Using a two-dimensional, high toroidal mode number eigenmode code employing a model tokamak equilibrium, it is shown that a window to second stability exists for a sufficiently deep magnetic well. The different mode structures o…
PublishedY. Nagayama K. Kawahata A. England Y. Ito N. Bretz et al.
The electron cyclotron emission ~ECE! diagnostic system is installed on the large helical device ~LHD!. The system includes the following instruments: a heterodyne radiometer, a Michelson spectrometer, and a grating polychromator. A 63.5 mm corrugated waveguide system is fully utilized. Large collection optics and notch filters at the frequency of …
PublishedN. J. Peacock K. D. Lawson R. Barnsley H. Chen
An empirical procedure, ‘‘LINT,’’ for relating emission line intensities of intrinsic impurity ions to their elemental contributions to the total, bolometric, radiation loss and the volume-averaged effective ion charge, Zeff , has been developed and applied to limiter plasmas in the JET tokamak. In this article we discuss extensions to the …
PublishedA. J. H. Donné T. Edlington E. Joffrin H. R. Koslowski C. Nieswand et al.
The polarimeter system for ITER features 10 viewing chords covering almost the full poloidal cross section of the plasma in a fan-like arrangement. The 10 laser beams all enter the plasma via 150 mm diam penetrations through the diagnostic plug at the low-field side. Small retroreflectors at the high-field side mirror the laser beams back towards t…
PublishedP. Helander S. C. Chapman R. O. Dendy G. Rowlands N. W. Watkins
A simple one-dimensional sandpile model is constructed which possesses exact analytical solvability while displaying both scale-free behavior and fractal properties. The sandpile grows by avalanching on all scales, yet its shape and energy content are described by a simple, continuous (but nowhere differentiable) analytical formula. The avalanche e…
Published