Method of controlling plasma in thermonuclear device

Purpose: To stably control a plasma so that the position and the shape of the plasma follow up function values relative to time given in advance. Constitution: A future coil current value is calculated by a coil current arithmetic unit based on a current applied to a toroidal coil for controlling a plasma, and a minor current control loop is controlled to be fed back through a comparator. A coil current value from the arithmetic unit, its differentiated value and present plasma horizontal position value from a plasma position detector are applied to a position arithmetic unit, which thus calculates a future plasma horizontal position value, thereby controlling the feedback of the major current control loop through the comparator. The unstability of controlling the coil having large time constant can be eliminated by this feedback control, thereby stably controlling the plasma. (Sekiya, K.)