Thermonuclear device and its operation method

A mechanism for a profile consistency uses a measuring device for measuring physical amounts such as distributions for the plasma pressure, density or temperature and judges whether plasmas show a distribution causing instability or not by a calculator. An instruction is issued to a heating device for supplying energy from the outside of plasmas, to induce plasma instability and saturate, thereby keeping the shape of the plasma distribution constant. The plasma instability can be controlled by using such a profile consistency mechanism. If the magnetohydrodynamic plasma instability such as sausage instability, kink instability, exchange type instability and tearing mode instability is developed and saturated, the pressure distribution, density distribution, or temperature distribution keeps a flat or moderate gradient constant distribution shape at the inside of a magnetic surface where rotational conversion is a rational number. Accordingly, equipments for suppressing the instability can be saved. (N.H.)