MACROSCOPIC STABILITY AND BETA LIMIT IN THE ELMO BUMPY TORUS

Magnetohydrodynamic stability limits are determined for the ELMO Bumpy Torus. The relativistic hot electron annuli are considered to be rigid, modifying the magnetic field, but not interacting with the instability. A modified energy principle is used, and the stability problem is reduced to determination of the eigenvalues of an ordinary differential equation along each field line. A threshold hot electron current is required for stability; its value agrees with experimental measurements. The calculations show that stable high-beta equilibria can be created. Experiments are being planned to test these predictions. © 1979 IOP Publishing Ltd.