Mitigation of disruptions in a tokamak by means of large gas injection

To study the basic physical processes of a disruption, a one-dimensional numerical model of particle and energy transport has been developed. Calculations for neon show that a fast penetration of the neutral gas can occur owing to the cooling of the plasma at the front of the neutral particle cloud. Assuming a large inward transport of the injected impurity of the order of 100 m"2/s, the radiated energy becomes equal to the thermal plasma energy prior to the disruption. After the thermal collapse, the plasma reaches an equilibrium temperature of several eV as a balance between ohmic heating, radiation and heat conduction losses. (orig.)SIGLEAvailable from TIB Hannover: RA 831(4122) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman