Measurment of Safety Factor and Poloidal Beta by Design and Fabrication of Emissive Limiter Bias in IR-T1 Tokamak

Abstract

In this paper, The first results of the movable emissive limiter biasing experiments performed on the IR-T1 Tokamak are presented. For this purpose, a moveable emissive limiter system was designed, constructed, and installed on the IR-T1 Tokamak. The emissive biased limiter is positioned at r/a=1.05, and the biased voltage which is varied from -350 to 350 V applied between the head of emissive limiter and vacuum chamber. Then, the plasma current, safety factor, poloidal beta and plasma resistance in the absence and presence of the emissive biased limiter in negative polarity were measured and results were compared with the cold limiter biasing in negative polarity. Much more plasma parameters such as the magneto hydrodynamics instability and plasma energy confinement time are determined by using these parameters. Diamagnetic loops and loop voltage can be utilized in measurements of the plasma poloidal beta and plasma resistance. Result are compared and discussed.