Poloidal coil for thermonuclear device

Purpose: To decrease errors in magnetic field by forming the poloidal coil with a one-turn coil conductor. Constitution: The poloidal coil is formed with a one-turn coil conductor. The one-turn coil conductor is initiated from the input end, circled for one-turn and ended at the output end, along which electric power supply line is provided. The electric power supply line is formed by three plate-like conductors arranged in parallel comprising an input line extending substantially vertical to the axial line of the coil conductor from the input end and two output lines extending in parallel with each other and substantially vertically to the above axial line from the output end. In the coil having the above structure, since the output lines are provided on both sides of the input line and the current through each of the electric power supply lines flows in opposite direction to each other, the structure is similar to that of the coaxial cable, which can decrease the generation of errors in the magnetic field. (Moriyama, K.)