Self-organization mechanism of the pressure profile at the internal disruption in heliotron plasmas

Using the soft x-ray tomographic analysis, the rapid change processes of the plasma profile are investigated at the internal disruption and following intermittent bursts. A relation between the coherent structure with a low mode number ( m = 2) and the local profile gradient is studied. It is found that there is a hysteresis relation between these. An explosive growth of the coherent mode and a functional dependence of the growth rate on the mode amplitude are also discussed