| 摘要 |
PURPOSE:To cool a Josephson computer circuit at a cryogenic temperature without generating a magnetic flux trap by mounting a cooling-rate controller by controlling the surface of liquid helium. CONSTITUTION:When liquid helium 7 is injected into a liquid helium vessel 8, a helium gas discharge control valve 14 and solenoid valves 16, 17 are closed previously. Even when the surface of liquid helium 7 rises, the surface of the liquid in an inside magnetic shielding vessel 3 does not ascend because helium gas remains in the vessel 3. When the control valve 14 is opened while the temperature of a computer circuit 1 is measured by a temperature sensor 11, liquid helium flows into the vessel 3, and begins to cool the computer circuit 1. The control valve 14 is controlled by a temperature control circuit 13 so that the computer circuit 1 and a superconducting magnetic shielding vessel 2 are cooled at cooling rates in an extent that a magnetic flux trap is not generated, and the inside of the vessel 3 is filled with liquid helium. |
