Some characteristics of the predisruption phase in the Damavand tokamak

The time evolution of magnetohydrodynamic activity, charge exchange neutral particles spectra, the line emission of the impurities in the visible spectral range and soft x-ray radiation were investigated in the predisruption phase of the small Damavand tokamak [Amrollahi , Plasma Phys. Rep. 23, 561 (1997)]. The experimental data show that the main disruptive processes, particularly the kinetic, take place near the plasma periphery. The experimental results also show that the interaction between high energy ions of bulk plasma and impurity ions may play an important role in the plasma radiation processes. A new mechanism for the plasma radiation processes in the predisruption phase may be obtained that can be considered for the investigation of the disruption instability. (C) 2001 American Institute of Physics.