EFFECT OF DISCHARGE CONDITIONS IN THE T-10 TOKAMAK ON ROTATION AND LOCKING OF MHD PERTURBATIONS IN A PLASMA

The rotation of the magnetic-island structure in a plasma was studied in detail in the T-10 tokamak. An operation diagram describing regimes , in which the locking of MHD perturbations occurred, was obtained, th e reproducible regimes being selected. The locking of the m = 2 mode u sually occurred when the perturbation with a sufficiently large amplit ude was in the fixed space position. The additional central plasma hea ting resulted in the substantial increase in the velocity of the rotat ion of the m = 2 mode and prevented the locking of this mode. When the heating power was sufficiently high, this prevented the development o f the disruptive instability due to the MHD-mode locking.