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Single beam, single detector diagnostic for plasma density profiles across a magnetic field gradient

Bellan, P. M. and Schalit, M. A. (1986) Single beam, single detector diagnostic for plasma density profiles across a magnetic field gradient. Physics of Fluids, 29 (11). pp. 3779-3784. ISSN 0031-9171. http://resolver.caltech.edu/CaltechAUTHORS:BELpof86

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Abstract

A scheme is proposed whereby the density profile of a tokamak or mirror plasma is mapped to nonlinear sidebands of a diagnostic wave, so that the sideband frequency spectrum is an image of the density profile traversed by the wave. The diagnostic relies on a monochromatic, high-frequency (omega>~omegace), pulsed wave source to determine the density profile across a magnetic field gradient. In principle, the technique offers time-dependent direct density profiles having high spatial resolution. However, the feasibility of the diagnostic is limited by the intense power and the rapid rise time required of the pulsed diagnostic wave. For parameters relevant to fusion plasmas, and for the particular scattering geometry suggested here, the technique requires, roughly, 30 mJ pulses of 2 nsec duration. The required power can be reduced by a factor of roughly 10^4 by applying signal averaging techniques. The rise time of the pulsed source must be short in comparison to one period of the diagnostic wave.


Item Type:Article
Additional Information:Copyright © 1986 American Institute of Physics. Received 23 July 1985; accepted 15 July 1986. One of the authors (M.A.S.) would like to thank Professor N.R. Corngold, Dr. P.C. Liewer, and Dr. W.A. Pebbles for useful discussions. This work was supported by the National Science Foundation under Grant No. ECS-8414541. One of the authors (M.A.S.) is the recipient of a Rockwell Fellowship.
Subject Keywords:PLASMA DENSITY, MAGNETIC FIELDS, PLASMA DIAGNOSTICS, TOKAMAK DEVICES, MAGNETIC MIRRORS, PLASMA, MAPPING, NONLINEAR PROBLEMS, RADIATION SOURCES, PULSES, TIME DEPENDENCE, SPATIAL RESOLUTION, POWER
Record Number:CaltechAUTHORS:BELpof86
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:BELpof86
Alternative URL:http://dx.doi.org/10.1063/1.865760
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9400
Collection:CaltechAUTHORS
Deposited By: Archive Administrator
Deposited On:18 Dec 2007
Last Modified:26 Dec 2012 09:48

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