PROBE DIAGNOSTIC COMPLEX OF TOKAMAK FT-2

摘要

Experimental investigations of peripheral processes in tokamak plasma are necessary to create a reliable theoretical model of the anomalous transverse particle and energy transport. These investigations take on particular interest in light of the discovery and intensive study of regimes with improved plasma confinement (H-mode), that have emphasized a close relationship between peripheral processes (specifically the nature of the peripheral microturbulence and particle fluxes attributed to it) and plasma parameters in the main part of a tokamak. It will be introduced the description of history of measuring probe device, diagnostic circuits of the FT-2 tokamak. Suggested method based on using of multi-electrode Langmuir probes provides time dependency of local parameters of peripheral plasma such as electron temperature, density of particles, potential of plasma, and also demonstrates behavior of particle drift. Using one of electrodes as high-frequency antenna gives an additional possibility to investigate an interaction of tokamak plasma and electromagnetic wave of low-hybrid diapason. Measurement technique is based on the use of three movable five-electrode Langmuir probes, located in the same transverse cross-section of the chamber, allowing obtaining data in the limiter shadow region inclusive the whole poloidal bypass of the torus. Diagnostic circuits provide the first processing of signal in frequency diapason up to 500 kHz without galvanic connection between probe electrodes and registration device. Diagnostic circuits also include the spectrum analyzer of electromagnetic radiation. Experimental results demonstrate the possibilities of the diagnostic complex.