Effects of Resonant Helical Field on Plasma Internal Inductance in IR-T1 Tokamak

Measurement of plasma internal inductance is important in tokamak plasma experiments (plasma internal inductance relates to the plasma current profile). In this paper we present an experimental investigation of effects of Resonant Helical Field (RHF) on the plasma internal inductance in IR-T1 tokamak. For this purpose, four magnetic probes and also a diamagnetic loop with its compensation coil were constructed and installed on outer surface of the IR-T1 tokamak, and Shafranov parameter, poloidal Beta, and then the internal inductance determined. In order to investigate the effects of RHF on internal inductance, we measured it in presence and also in absence of different modes of the RHF (L = 2, L = 3, L = 2&3). Experimental results show that L = 3 mode can flat the plasma current and increase the plasma internal inductance.