Thermonuclear alfven instabilities in a tokamak reactor

A study has been made into Alfven thermonuclear instabilities of a tokamak reactor, related to disturbances whose longitudinal wavelength lambda = 2π/k is less or order of the length of the magnetic line of force on the torus circumference 2πqR, i.e., kqR > or approximately 1 (k is the longitudinal wave number, R is the radius of the torus magnetic axis, and q is the tokamak stability factor). Corresponding to such disturbances are, for example, the instability of flight alpna particles on cyclotron resonance and that of trapped alpha particles at low-frequency bounce-resonances. Also studied is the effect of the toroidal shape on the former instability, and it is shown that the right magnetic field approximation can be used for this study. The problem of thresholds of instabilities due to the damping of Alfven waves on trapped electrons is discussed