Confinement and stability
Confinement time is finite - neoclassical (collisional) transport.
Simple scaling argument leads to:
- If a>>?D, confinement is excellent, but still finite
- Confinement time can be much longer if the magnetic field is carefully tailored (stellarator quasi-symmetry).
- If indeed the equilibrium is a minimum energy state, then dissipation will not destabilize the plasma
- In a magnetic surface configuration, diocotron modes will excite plasma oscillations along the magnetic field. These will be Landau damped provided the temperature is not negligibly small.
- Magnetic shear also acts to stabilize diocotron modes1
1. S. Kondoh, T. Tatsuno, and Z. Yoshida, Phys. Plasmas 8, 2635 (2001).