| 摘要 |
PURPOSE:To prevent both the burning loss of the coil itself at the quenching time and the increment of the container's inner voltage by reducing the resistance value of the protective resistance provided outside the container storing the superconductive coil less sufficiently than the resistance value of the permanent current switch at the off-time. CONSTITUTION:Both superconductive coil 1 and permanent current switch 5 are stored in cryostat 2. When the permanent current operation is started with excitation of coil 1, coil 1 is cut off from the power source via terminal 6 and 6'. But in case coil 1 is quenched under operation of the permanent current, it is detected by quench detector 7. And permanent current switch operation part 8 is actuated to open swith 5, and the current of coil 1 flows to protective resistance 4. In this case, the value of resistance 4 is set small enough to the resistance of switch 5 at the off-time when the resistance connection is given to switch 5 with the circuit not opened like the thermal permanent current switch. Thus, the energy discharged within cryostat 2 can be reduced. |
