A dilution refrigerator is provided. The dilution refrigerator includes a plurality of thermalization plates configured to be cooled to a plurality of temperatures, and a first thermalization plate of the plurality of thermalization plates includes an integrated heat exchanger. The integrated heat exchanger includes channels formed in the first thermalization plate, and the channels are configured to allow helium to flow through the first thermalization plate during operation of the dilution refrigerator to improve heat exchange and cooling power of the dilution refrigerator.

A dilution refrigerator is provided. The dilution refrigerator includes a plurality of thermalization plates configured to be cooled to a plurality of temperatures, and a first thermalization plate of the plurality of thermalization plates includes an integrated heat exchanger. The integrated heat exchanger includes channels formed in the first thermalization plate, and the channels are configured to allow helium to flow through the first thermalization plate during operation of the dilution refrigerator to improve heat exchange and cooling power of the dilution refrigerator.

The present disclosure relates to a cryogenic apparatus (300, 400, 500), comprising: at least one first temperature change mechanism (310, 410) connected to a sample stage (20) and configured to change a temperature at the sample stage (20); at least one second temperature change mechanism (320, 420, 520, 522) different from the at least one first temperature change mechanism (310, 410), wherein the at least one second temperature change mechanism (320, 420, 520, 522) is connected to the sample stage (20) and configured to change the temperature at the sample stage (20); and a controller. The controller is configured to: operate the at least one first temperature change mechanism (310, 410) in a first temperature range (A); operate the at least one second temperature change mechanism (320, 420, 520, 522) in a second temperature range (B) different from the first temperature range (A); and operate both the at least one first temperature change mechanism (310, 410) and the at least one second temperature change mechanism (320, 420, 520, 522) in a third temperature range (C) between the first temperature range (A) and the second temperature range (B).

A cryogenic cooling system is provided comprising: a cooled plate (2) thermally coupled to a cryogenic refrigerator (9), a heat switch assembly and a target assembly (5). The target assembly (5) comprises a target refrigerator (12) configured to obtain a lower base temperature than the cryogenic refrigerator (9). The heat switch assembly (18) comprises one or more gas gap heat switches, the heat switch assembly (18) having a first end thermally coupled to the cooled plate (2) and a second end thermally coupled to the target assembly (5). A sorption pump (22) is provided for controlling the thermal conductivity across the heat switch assembly (18) in accordance with the temperature of the sorption pump (22) The sorption pump (22) is thermally coupled to the cryogenic refrigerator (9), by a thermal link (46) extending from the cooled plate (2) to the heat switch assembly (18). The sorption pump (22) is arranged at a position along the thermal link (46) between the heat switch assembly 18 and the cooled plate (2).

A cryogenic cooling system is provided comprising: a cooled plate (2) thermally coupled to a cryogenic refrigerator (9), a heat switch assembly and a target assembly (5). The target assembly (5) comprises a target refrigerator (12) configured to obtain a lower base temperature than the cryogenic refrigerator (9). The heat switch assembly (18) comprises one or more gas gap heat switches, the heat switch assembly (18) having a first end thermally coupled to the cooled plate (2) and a second end thermally coupled to the target assembly (5). A sorption pump (22) is provided for controlling the thermal conductivity across the heat switch assembly (18) in accordance with the temperature of the sorption pump (22) The sorption pump (22) is thermally coupled to the cryogenic refrigerator (9), by a thermal link (46) extending from the cooled plate (2) to the heat switch assembly (18). The sorption pump (22) is arranged at a position along the thermal link (46) between the heat switch assembly 18 and the cooled plate (2).

A cryogenic cooling system is provided comprising a primary insert (118) and a demountable secondary insert (128). The primary insert (118) comprises a plurality of primary plates (111, 112), each primary plate having a primary contact surface, and one or more primary connecting members (117) arranged so as to connect the plurality of primary plates (111, 112). The demountable secondary insert (128) comprises a plurality of secondary plates (121, 122), each secondary plate having a secondary contact surface, and one or more secondary connecting members (127) arranged so as to connect the plurality of secondary plates (121, 122) such that the secondary insert (128) is self-supporting. One or more adjustment members are configured such that, when the secondary insert (128) is mounted to the primary insert (118), the adjustment members cause the primary and secondary contact surfaces of the respective primary (111, 112) and secondary plates (121, 122) to be brought into conductive thermal contact.

A cryogenic cooling system is provided comprising a primary insert (118) and a demountable secondary insert (128). The primary insert (118) comprises a plurality of primary plates (111, 112), each primary plate having a primary contact surface, and one or more primary connecting members (117) arranged so as to connect the plurality of primary plates (111, 112). The demountable secondary insert (128) comprises a plurality of secondary plates (121, 122), each secondary plate having a secondary contact surface, and one or more secondary connecting members (127) arranged so as to connect the plurality of secondary plates (121, 122) such that the secondary insert (128) is self-supporting. One or more adjustment members are configured such that, when the secondary insert (128) is mounted to the primary insert (118), the adjustment members cause the primary and secondary contact surfaces of the respective primary (111, 112) and secondary plates (121, 122) to be brought into conductive thermal contact.

Dilution refrigeration device and method comprising a loop working circuit containing a working fluid comprising a mixture of helium-3 (3He) and helium-4 (4He), the working circuit comprising, arranged in series and fluidically connected via a first set of pipes, a mixing chamber, an evaporator and transfer member, the first set of pipes being configured to transfer the working fluid from an outlet of the mixing chamber to an inlet of the evaporator and from an outlet of the evaporator to an inlet of the transfer member, the working circuit comprising a second set of pipes connecting an outlet of the transfer member to an inlet of the mixing chamber, the working circuit comprising at least a first heat-exchange portion for exchange of heat between at least part of the first set of pipes and the second set of pipes, the first heat-exchange portion being situated between the evaporator and the mixing chamber, the device further comprising at least one cooling member in a heat-exchange relationship with the working circuit, the device comprising at least one cryogenic pumping member situated in the working circuit between the evaporator and the transfer member.

A method of chemical vapor infiltration and deposition includes disposing a porous substrate within a reaction chamber, establishing a sub-atmospheric pressure within the reaction chamber, introducing a hydrocarbon reaction gas into a reaction zone of the reaction chamber to densify the porous substrate, withdrawing unreacted hydrocarbon reaction gas from the reaction chamber, the unreacted hydrocarbon reaction gas comprising hydrocarbon molecules having six or more carbon atoms, removing at least a portion of the hydrocarbon molecules having six or more carbon molecules from the unreacted hydrocarbon reaction gas by causing the portion of the hydrocarbon molecules having six or more carbon atoms to condense, and recirculating at least a portion of the unreacted hydrocarbon reaction gas back into the reaction zone.

A method of chemical vapor infiltration and deposition includes disposing a porous substrate within a reaction chamber, establishing a sub-atmospheric pressure within the reaction chamber, introducing a hydrocarbon reaction gas into a reaction zone of the reaction chamber to densify the porous substrate, withdrawing unreacted hydrocarbon reaction gas from the reaction chamber, the unreacted hydrocarbon reaction gas comprising hydrocarbon molecules having six or more carbon atoms, removing at least a portion of the hydrocarbon molecules having six or more carbon molecules from the unreacted hydrocarbon reaction gas by causing the portion of the hydrocarbon molecules having six or more carbon atoms to condense, and recirculating at least a portion of the unreacted hydrocarbon reaction gas back into the reaction zone.