Optical Probe for Local Measurements of Plasma Velocity

G. Fiksel, D. J. Den Hartog, P. Fontana

University of Wisconsin - Madison
Department of Physics

A device for local sampling of plasma radiation is described. The radiation is observed with two fused silica bundles with the lines of views crossing at 90°. Each line of view is terminated by a view dump, thus  achieving the locality. The spatial resolution is about 5cm. The device is arranged in the form of an insertable probe protected from the plasma by a Boron Nitride enclosure, therefore the radial profiles can be measured. The plasma velocity is deduced by the red and blue Doppler shifts of the corresponding radiation spectra. All three components of the velocity - radial, poloidal, and toroidal can be measured. The range of the probe applications includes the studies of fluctuation driven transport, the RFP dynamo, and ion viscosity. Initial velocity measurements in MST using the He II 468.6 nm line are presented.

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Email to G. Fiksel (gfiksel@facstaff.wisc.edu)

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