Thermonuclear device

Purpose: To facilitate the exchange of a pump limiter disposed as a counter measure for the plasma impurities, and reduce the size of magnetic coils. Method: While the space in toroidal magentic coils is utilized for the exchange of a pump limiter, if the space is intended to enlarge for facilitating the exchanging work, the shape of the magnetic coils is enlarged and the power source capacity is also increased. The vessels for the inner toroidal coils and the vessels for the outer toroidal coils putting the vacuum vessel therebetween are made into trapezoidal configuration respectively, and they are moved in parallel with respect to the center of the vacuum vessel such that the upper side of the outer vessel is opposed to the lower side of the inner vessel. As the result, the size of the toroidal magnetic coils can be reduced while neither diminishing the space for the exchanging work nor increasing the working time for the exchange of the pump limiter. (Moriyama, K.)