Experimental Study of High-beta Equilibrium Transition of ST Plasmas during Merging/Reconnection Heating

Abstract

The reconnection/merging of two spherical tokamak (ST) plasmas is found to transform their low-beta ST equilibria with peaked current density profiles to a single high-beta one with hollow current density profile. Our 2D magnetic probe measurement reveals formation of 2D ring-type hollow current density profile of the produced ST using reconnection current at around X-point.