PSFC/JA-06-32 Effects of finite poloidal gyroradius, shaping, and collisions on the zonal flow residual
نویسندگان
چکیده
Zonal ow helps reduce the turbulent transport level in tokamaks. Rosenbluth and Hinton have shown that zonal ow damps to to a non-vanishing residual level in collisionless and collisional banana regime plasmas Recent zonal ow advances are summarized including the evaluation of the e¤ects on this zonal ow residual of plasma cross section shaping, shorter wavelengths including those less than an electron gyroradius, and aritrary collisionality relative to the zonal low frequency. In addition to giving a brief summary of these new developments, the analytic results are compared with GS2 numerical simulations to demonstarte their value as benchmarks for turbulence codes.
منابع مشابه
PSFC/JA-06-20 Short wavelength effect on the collisionless neoclassical polarization and residual zonal flow level
Sheared zonal ow helps to reduce the turbulent transport caused by the ion temperature gradient (ITG) mode. Rosenbluth and Hinton (R-H) calculated the residual zonal ow level for radial wavelengths that are much larger than the ion poloidal gyroradius. Their calculation is extended to treat arbitrary radial wavelengths. For the radial wavelengths that approach the ion poloidal gyroradius, but...
متن کاملEffects of finite poloidal gyroradius, shaping, and collisions on the zonal flow residual
Zonal flow helps reduce and regulate the turbulent transport level in tokamaks. Rosenbluth and Hinton have shown that zonal flow damps to a nonvanishing residual level in collisionless M. Rosenbluth and F. Hinton, Phys. Rev. Lett. 80, 724 1998 and collisional F. Hinton and M. Rosenbluth, Plasma Phys. Control. Fusion 41, A653 1999 banana regime plasmas. Recent zonal flow advances are summarized ...
متن کاملPSFC / JA - 06 - 25 Plasma shaping effects on the collisionless residual zonal flow level
Plasma shaping e¤ects, such as elongation, triangularity and Shafranov shift have long been considered an important ingredient in improving tokamak performance. It is known that the growth rate of ion temperature gradient (ITG) turbulence can be regulated by these shaping e¤ects and that the ITG turbulence level can also be regulated by zonal ‡ow. Moreover, recent numerical simulation shows tha...
متن کاملKinetic Effects in the Pedestal of a Tokamak
We consider the effects of finite ExB on the residual and neoclassical ion heat transport and ion flow in the pedestal. For a tokamak pedestal with a density scale of the poloidal ion gyroradius the finite ExB drift modfies the ion orbits, moving the trapped-passing boundary towards the tail of the ion distribution function. Introduction In many tokamak plasmas the width of the pedestal is obse...
متن کاملPSFC / JA - 10 - 2 Trajectories , orbit squeezing , and residual zonal flow in a tokamak pedestal
Particle orbits and the Rosenbluth-Hinton residual zonal flow are evaluated for the case of a strong equilibrium radial electric field ( ) / r E d d φ ψ ψ = − ∇ as observed in a tokamak pedestal. The ordering used is p i ~ / r E B v c where p B is the poloidal field and i v is the ion thermal speed. The earlier calculations of Kagan and Catto for this regime [Kagan G and Catto P J 2009 Phys. Pl...
متن کامل