Experimental Measurements of the Current, Temperature, and Density Profile Changes during a Disruption in the DIII-D Tokamak

The first simultaneous measurements of the current, temperature, and density profile changes during a disruption have now been made on the DIII-D tokamak. In radiative collapse disruptions the current profile measured using the motional Stark effect diagnostic is observed to flatten rapidly ( ~1.2 ms) at the final stage of a 10 ms thermal quench and just prior to the start of the current quench. The current flattening is faster than can be explained by relaxation due to classical or neoclassical resistive processes.