Filamentary probe on the COMPASS tokamak.

ABSTRACT

This paper describes a new filamentary probe recently introduced on the COMPASS tokamak. It allows the measurement of electrostatic and magnetic properties of the filaments and their changes in dependence on distance from the separatrix in the region between a divertor and midplane. The probe head is mounted on a manipulator moving the probe radially on a shot-to-shot basis. This configuration is suitable for the long term statistical measurement of the plasma filaments and the measurement of their evolution during their propagation from the separatrix to the wall. The basics of the filamentary probe construction, the evolution of the plasma parameters, and first conditional averages of the plasma filaments in the scrape-off layer of the COMPASS tokamak during the L-mode regime are presented.