| 摘要 |
PURPOSE:To suppress the generation of thermal stress caused by the temperature difference by the introduction of unused low temperature helium gas into gas piping installed in a helium gas passage within a coil container. CONSTITUTION:Gas piping 5 is provided in a gas passage extended from a gas inlet outside a coil conductor 3. The base of the piping 5 is connected to the portion introducing the gas in a coil container 1 and each pipe is allowed to have different length so as to effectively cool the upper portion of the coil. In so doing, low temperature helium gas 2 supplied from the lower portion of the coil moves upward in the piping 5 without decreasing its cooling capability and reaches the pipe outlet. Since the low temperature gas 2 will not cool the conductor 3 and the container 1 while passing through the piping 5, the temperature of the gas at the pipe outlet is kept as low as what has been initially supplied, so that it can thoroughly cool the coil conductor and the coil container located near the pipe outlet. |
