Thermonuclear device

Purpose: To uniformly bake the bellows provided for thermal expansion absorption in a toroidal vacuum vessel with no hinderance to the bellows' deformation. Constitution: The outer circumference of bellows is covered with a flexible heat insulation material that does not hinder the bellows from deformation and a heater for supplementing heat radiated from the bellows upon baking is provided in the heat insulating material. The heat insulation material employed is a cotton like material such as asbestos, or glass wool. Baking for the bellows is conducted by way of heat conduction from a heater provided other than in the bellows and the heater provided in the bellows is utilized for supplementing the amount of heat dissipated from the bellows. (Ikeda, J.)