Torus type thermonuclear devices

Purpose: To obtain highly efficient poloidal coils capable of withstanding great stresses. Constitution: Poloidal magnetic coils are made of a plurality of hard copper conductors metallurgically fastened to each other and the metallurgical fastening portions are disposed at a position about 0.21 pitch for the coil support members from the supporting point for the coil supports. Since the synthetic stresses applied to the coils upon generation of magnetic fields can thereby minimized, the endurance of the softened portions of the coils is not substantially decreased as compared with other portions, whereby highly efficient poloidal coils capable of withstanding great stresses can be obtained. (Moriyama, K.)