Controlled high density operation on ASDEX upgrade by pellet refuelling from the magnetic high-field side
A novel, highly efficient tokamak plasma refuelling scenario with cryogenic deuterium (D) pellets injected from the magnetic high-field side was applied for the first time to demonstrate feedback-controlled operation beyond the empirical Greenwald density limit. The H-mode was maintained during high density operation with an energy confinement time normalized to the ELMy H-mode 0.85 * ITERH93P scaling of above 0.82. The density gradient at the plasma edge already achieved during the pre-pellet H-mode phase shows no significant increase during the pellet induced increase of plasma inventory. The particle flux through the edge is about 5 times higher during the pellet phase than before. This seems to indicate a strong increase of the particle diffusivity at the plasma edge enforced by the pellet particle source.
Bibliographic Reference: Report: IPP 1/314 EN (1998) 23pp.
Availability: Available from the Max-Planck-Institut für Plasmaphysik, 85748 Garching bei München (DE)
Record Number: 199810606 / Last updated on: 1998-05-12
Original language: en
Available languages: en