Publication

Toroidally localized and nonlocalized ballooning instabilities in a stellarator

Wilfred Anthony Cooper
1998
Journal Articles

Abstract

It is shown that the coexistence of toroidally nonlocalized ideal-hydromagnetic ballooning instabilities, with a quasidiscrete spectrum, and toroidally localized ballooning instabilities with a broad continuous spectrum, as predicted by Dewar and Glasser [Phys. Fluids 26, 3038 (1983)] can be realized in a Mercier-unstable equilibrium case modeling the Large Helical Device (LHD) [A. Iiyoshi et al., Fusion Technol. 17, 148 (1990)] with a broad pressure profile. The quasidiscrete, interchange branch corresponds to extended modes that can be understood on the basis of a ripple-averaged ballooning equation, whereas the broad-continuum, ballooning branch corresponds to modes localized along a flux tube, The physical origin of the two branches is discussed. (C) 1998 American Institute of Physics.

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https://infoscience.epfl.ch/entities/publication/ab1fd854-881a-49a0-b5c2-2ee397f6463a

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Wilfred Anthony Cooper
1998
Journal Articles

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/ab1fd854-881a-49a0-b5c2-2ee397f6463a

About this result

Related concepts (11)

Visible spectrum

The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 380 to about 700 nanometers. In terms of frequency, this corresponds to a band in the vicinity of 400–790 terahertz. These boundaries are not sharply defined and may vary per individual. Under optimal conditions these limits of human perception can extend to 310 nm (ultraviolet) and 1100 nm (near infrared).

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A spectrum (: spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. As scientific understanding of light advanced, it came to apply to the entire electromagnetic spectrum. It thereby became a mapping of a range of magnitudes (wavelengths) to a range of qualities, which are the perceived "colors of the rainbow" and other properties which correspond to wavelengths that lie outside of the visible light spectrum.

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Related publications (1)

Toroidally localized and nonlocalized ballooning instabilities in a stellarator

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Multimachine analysis of intermittent fluctuations in the scrape-off layer of magnetically confined fusion plasmas