Analogies of Rapidly Rotating Tokamaks and Accretion Disks
Abstract
Equilibrium, waves, and instabilities of tokamaks and accretion disks that are rotating with arbitrary transonic velocities have been solved by means of advanced numerical and analytical techniques. The different transonic flow regimes yield a surprisingly large number of new MHD waves and instabilities that (1) are relevant for turbulent processes in accretion disks, (2) provide a clear correspondence between tokamaks and accretion disk dynamics, with different influence of rotation profiles, gravity, and magnetic pressure, (3) provide a new angle on rapid transition phenomena in transonic MHD flows of rotating astrophysical plasmas. The new angle entails a complete revision of all previously obtained spectral results. The reason is that transonic flows upset the standard theoretical approach to plasma dynamics, consisting of a separate study of the equilibrium state and of the perturbations of this background. We will discuss a new approach to this dichotomy consisting of a study of the similarities of the nonlinear stationary flow patterns and the different linear wave structures that occur when the background speed traverses the full range of critical speeds (from `slow magnetosonic' to `Alfvén' to `fast magnetosonic'). This has required the development of new computational tools that yield the mentioned plethora of new waves and instabilities.
- Publication:
-
Plasma Physics
- Pub Date:
- June 2003
- DOI:
- 10.1063/1.1594012
- Bibcode:
- 2003AIPC..669..642G
- Keywords:
-
- 52.30.Cv;
- 52.35.Ra;
- 52.55.Fa;
- 95.30.Qd;
- Magnetohydrodynamics;
- Plasma turbulence;
- Tokamaks spherical tokamaks;
- Magnetohydrodynamics and plasmas