ELM phenomenon as an interaction between bootstrap-current driven peeling modes and pressure-driven ballooning modes
An ELMy ASDEX Upgrade plasma equilibrium is reconstructed taking into account the bootstrap current. The peeling mode stability of the equilibrium is numerically analyzed using the GATO  code, and it is found that the bootstrap current can drive the plasma peeling mode unstable. A high-n ballooning mode stability analysis of the equilibria revealed that, while destabilizing the peeling modes, the bootstrap current has a stabilizing effect on the ballooning modes. A combination of these two instabilities is a possible explanation for the type I ELM phenomenon. A triangularity scan showed that increasing triangularity stabilizes the peeling modes and can produce ELM-free periods observed in the experiments.
Bibliographic Reference: Article: Plasma Physics Controlled Fusion, Vol. 42 (2000) pp. A139-A145
Availability: Plasma Physics Controlled Fusion (Journal)
Record Number: 200012121 / Last updated on: 2000-07-12
Original language: en
Available languages: en