Return To: Session THP2 - Theory 2 (Transport)
Prev Page: (THP2/23) Global Alfvén Eigenmodes Stability in Thermonuclear Tokamak
Next Page: (THP2/25) Behavior of MeV Ions in the Presence

(THP2/24) Stability Analysis of Energetic Ion Alfvén Mode and Kinetic Ballooning Mode in Tokamaks

A. Hirose, M. Elia

Plasma Physics Laboratory, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada

M. Yamagiwa
Advanced Photon Research Center, Japan Atomic Energy Research Institute, 2-4 Tokai, Naka, Ibaraki 319-1195, Japan

Abstract.  Kinetic ballooning analysis has been performed for high performance tokamak discharges by implementing the Shafranov shift $\Delta{^\prime}$ in both positive and negative shear regimes. For discharge parameters pertinent to the transport barriers characterized by steep pressure gradient and large $\Delta{^\prime}$, the kinetic ballooning and drift type modes are stabilized at $\Delta{^\prime}$ $\simeq$ - 0.3 $\sim$ - 0.2. A new MHD type ballooning mode with large growth rates is predicted for excessively large $\Delta{^\prime}$ in negative shear regime. Also investigated is the Alfven mode driven by energetic ions (such as trapped alpha particles) without resorting to the conventional ideal MHD assumption for the bulk ions. Compared with earlier predictions, a reduction in the growth rate by two orders of magnitude has been seen.

Read the full paper in PDF format.