LONG WAVELENGTH DENSITY FLUCTUATIONS IN A TOKAMAK PLASMA
In very far forward scattering experiments on TOSCA tokamak in which 10.6 mum wavelength laser radiation is directed across a vertical minor diameter, oscillations induced on the beam profile by plasma density fluctuations are found to be asymmetric with respect to the beam axis. A model describing counter-rotating waves, such as a poloidal structure met twice by the probe beam as it traverses the plasma is able to furnish a satisfactory fit to the data. Coherent modes, identified as rotating m=2 magnetic islands are seen, as well as wideband fluctuations whose power spectrum falls as v**-2.5. Wavelengths from 0.2 cm to 10 cm are measured, and waves at the top of the torus appear to be twice as intense as those at the bottom.
Bibliographic Reference: 2ND INTERNATIONAL SYMPOSIUM ON LASER AIDED PLASMA DIAGNOSTICS, CULHAM (UK), SEPT. 10-12, 1985 PP. 85-89
Record Number: 1989124103600 / Last updated on: 1987-01-01
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