Operation method of thermonuclear device

This invention concerns a method of operating a thermonuclear device having a divertor arrangement in a highly efficient heating mode. When the plasma pressure gradient near the surface of plasmas reaches such a value as causing edge localized mode (ELM) phenomenon (a phenomenon that Hα-ray intermittently increases it intensity), the energy loss from the plasma surface is artificially increased to reduce the plasma pressure ingredient thereby stably confine the plasmas. According to the operation method, the pressure gradient near the surface of the plasmas can be controlled in a highly efficient heating mode. The instable ELM phenomenon near the surface of the plasmas can be suppressed. Accordingly, there is an effect for stably confining the plasmas. Therefore, it is possible to avoid such undesirable phenomenon that the plasmas are brought into contact with limiters or high frequency antenna, the coupling preperty between the high frequency of the plasma is changed or the thermonuclear power is fluctuated. (K.M.)