Study of second stability regime for ITG modes in tokamaks
Ion-temperature-gradient (ITG) modes in tokamaks are stabilized when the plasma diamagnetism at high pressure reverses the magnetic drifts; this stabilization is studied in the trapped-ion and toroidal ITG regimes with a linear global gyrokinetic particle-in-cell code that uses the full magnetohydrodynamic (MHD) equilibrium data. It is found that a magnetic drift reversal parameter that scales like the gradient of the normalized pressure, beta, describes the stabilization well, better than the standard ballooning parameter that scales like the Shafranov shift and poloidal pressure. There exists a window of simultaneous second stability for MHD ballooning modes and ITG modes. Stability to global kink modes, in the presence of an ideal wall outside the plasma, is obtained for cases with high temperature gradients and with ITG growth rates that are an order of magnitude lower than at low plasma pressure.
Bibliographic Reference: Article: Physics of Plasmas (1998)
Record Number: 199810537 / Last updated on: 1998-05-05
Original language: en
Available languages: en