The evolution of the plasma current during tokamak disruptions
In a tokamak disruption, the Ohmic plasma current is partly replaced by a current carried by runaway electrons. This process is analysed by combining the equations for runaway electrons generation with Maxwell's equations for the evolution of the electric field. This allows a quantitative understanding to be gained of runaway production in present experiments, and extrapolation to be made to ITER. The runaway current typically becomes more peaked on the magnetic axis than the pre-disruption current. In fact, the central current density can rise, although the total current falls, which may have implications for post-disruption plasma stability. Furthermore, it is found that the runaway current easily becomes radially filamented due to the high sensitivity of the runaway generation efficiency to plasma parameters.
Bibliographic Reference: An oral paper given at: 31st EPS Conference on Controlled Fusion and Plasma Physics Organised by: CCLRC Rutherford Appleton Laboratory (GB); EURATOM/UKAEA Fusion Association (GB) Held at: Imperial College London(GB)
Availability: Available from Association EURATOM-CEA, Departement de Recherches sur la Fusion Controlee, CEA Cadarache, F-13108 St Paul-Lez-Durance, France Tel: (+33) 4 42 25 70 01; Fax: (+33) 4 42 25 64 21 E-mail: email@example.com
Record Number: 200417671 / Last updated on: 2004-07-30
Original language: en
Available languages: en