Author/Authors :
Gunn، نويسنده , , J.P. and Petr??lka، نويسنده , , V. and Ekedahl، نويسنده , , A. and Fuchs، نويسنده , , V. and Gauthier، نويسنده , , E. and Goniche، نويسنده , , M. and Ko?an، نويسنده , , M. and Pascal، نويسنده , , M.-G. Saint-Laurent، نويسنده , , F.، نويسنده ,
Abstract :
A retarding field analyzer was used to provide direct measurements of the particle and power fluxes of suprathermal electrons in hot spots that are magnetically connected to the region in front of the waveguides of a lower hybrid antenna in Tore Supra. Hot spots can be divided into two regions according to the temporal evolution of the local suprathermal electron flux. Adjacent to each waveguide row is a layer of strong, dc current on which is superimposed strong fluctuations. Deeper into the plasma a second type of electron flux is identified: highly intermittent (∼10 kHz) bursts separated by brief periods of zero flux. Electron bursts occur at least up to 40–50 mm in front of the grill mouth. These observations contradict the standard theory that predicts that hot spots should be at most ∼5 mm wide.
