A heat exchanger for a cryogenic cooling apparatus is provided. The heat exchanger has a first conduit, a second conduit and a chamber, wherein the chamber is arranged to receive a fluid from the first conduit, and wherein second conduit is thermally coupled to the outside of the chamber. The chamber has a first region and a second region, the first region separated from the second region by a plate extending through the chamber, the plate comprising one or more apertures for allowing a flow of the fluid from the first region to the second region.

A heat exchanger for a cryogenic cooling apparatus is provided. The heat exchanger has a first conduit, a second conduit and a chamber, wherein the chamber is arranged to receive a fluid from the first conduit, and wherein second conduit is thermally coupled to the outside of the chamber. The chamber has a first region and a second region, the first region separated from the second region by a plate extending through the chamber, the plate comprising one or more apertures for allowing a flow of the fluid from the first region to the second region.

A quantum computing system includes a dilution refrigerator having a plurality of chambers. A trapped ion computing device includes a first set of qubits in a given chamber of the plurality of chambers of the dilution refrigerator. A superconducting computing device having a second set of superconducting qubits is inside the given chamber of the plurality of chambers of the dilution refrigerator.

A quantum computing system includes a dilution refrigerator having a plurality of chambers. A trapped ion computing device includes a first set of qubits in a given chamber of the plurality of chambers of the dilution refrigerator. A superconducting computing device having a second set of superconducting qubits is inside the given chamber of the plurality of chambers of the dilution refrigerator.

A device intended for cooling an object being moved within a cryostat comprises a heat transfer section forming a contact surface for said object and means for fastening the heat transfer section to a cooling structure in such a way that said contact surface remains free. The device comprises a spring section which is separate from said heat transfer section and which is arranged to exert on the heat transfer section a spring force pushing said contact surface in a direction in which it is intended to contact said object.

A device intended for cooling an object being moved within a cryostat comprises a heat transfer section forming a contact surface for said object and means for fastening the heat transfer section to a cooling structure in such a way that said contact surface remains free. The device comprises a spring section which is separate from said heat transfer section and which is arranged to exert on the heat transfer section a spring force pushing said contact surface in a direction in which it is intended to contact said object.

A pulse tube cryocooler includes a cold head including a pulse tube and a radiator thermally coupled to a high-temperature end of the pulse tube, and a forced cooler that forcedly cools the radiator in a cool-down operation of the pulse tube cryocooler from an ambient temperature to a cryogenic temperature.

A distributed refrigeration system is provided. The distributed refrigeration system comprises a pre-cooling system configured to be thermally coupled to two or more cryogenic devices and to provide a first cooling stage to the two or more cryogenic devices. The two or more cryogenic devices may be two or more of a dilution refrigerator, a low-temperature microscopy system, a .sup.3He refrigeration system, and/or a superconducting CMOS system.

A distributed refrigeration system is provided. The distributed refrigeration system comprises a pre-cooling system configured to be thermally coupled to two or more cryogenic devices and to provide a first cooling stage to the two or more cryogenic devices. The two or more cryogenic devices may be two or more of a dilution refrigerator, a low-temperature microscopy system, a .sup.3He refrigeration system, and/or a superconducting CMOS system.

In a cryocooler for developing coldness of 4 K or lower by expanding helium, an expander expands high-pressure helium. A compressor compresses low-pressure helium returned from the expander, to generate high-pressure helium, and supplies the high-pressure helium to the expander. When helium temperature in the expander is 2.17 K or lower, the pressure of the low-pressure helium is equal to or higher than pressure given by a curve, in a helium state diagram in which the horizontal axis is temperature and the vertical axis is pressure, along which helium's volumetric thermal expansion coefficient is 0.