Systems, methods, and apparatus for cryogenic refrigeration
View Patent ↗Cryogenic refrigeration employs a pulse tube cryo-cooler and a dilution refrigerator to provide very low temperature cooling, for example, to cool superconducting processors. Continuous cryogenic cycle refrigeration may be achieved using multiple adsorption pumps. Various improvements may include multiple distinct thermal-linking points, evaporation pots with cooling structures, and/or one or more gas-gap heat switches which may be integral to an adsorption pump. A reservoir volume may provide pressure relief when the system is warmed above cryogenic temperature, reducing the mass of the system. Additional heat exchangers and/or separate paths for condensation and evaporation may be provided. Multi-channel connectors may be used, and/or connectors formed of a regenerative material with a high specific heat capacity at cryogenic temperature. Flexible PCBs may provide thermal links to components that embody temperature gradients. Various components may be pre-cooled, for example via a switchable thermalization system.
1. A cryogenic cycle refrigeration system comprising:
a first adsorption pump and a second adsorption pump, both the first and the second adsorption pumps including a respective quantity of adsorbent material;
a plurality of tubular channels each capable of providing fluid passage therethrough, wherein a first one and a second one of the tubular channels both include a respective condensation region, the respective condensation regions each thermally coupled to at least one cold source within the refrigeration system;
a first evaporation pot and a second evaporation pot, each of the first and the second evaporation pots coupled to a respective one of the first and the second adsorption pumps by a respective one of the first and the second tubular channels;
a heat exchanger that provides thermal coupling between at least two of the tubular channels; and
a third tubular channel and a fourth tubular channel, the third tubular channel coupled in parallel with the first tubular channel to provide fluid communication between the first adsorption pump and the first evaporation pot, and the fourth tubular channel coupled in parallel with the second tubular channel to provide fluid communication between the second adsorption pump and the second evaporation pot, and wherein the heat exchanger includes a first thermal link coupled between the first and the fourth tubular channels and a second thermal link coupled between the second and the third tubular channels.
2. The refrigeration system of claim 1 , further comprising:
a first and a second quantity of coolant substance, each of the first and the second quantities of coolant substance contained within a respective one of the first and the second evaporation pots.
3. The refrigeration system of claim 2 wherein each of the first and the second quantities of coolant substance is selected from a group consisting of helium-3 and helium-4.
4. The refrigeration system of claim 1 , further comprising a pulse tube cryo-cooler, wherein the respective condensation regions are each thermally coupled to the pulse tube cryo-cooler and wherein the heat exchanger is thermally coupled to the first one of the tubular channels at a point that is positioned in between the condensation region of the first one of the tubular channels and the first evaporation pot and the heat exchanger is thermally coupled to the second one of the tubular channels at a point that is positioned in between the condensation region of the second one of the tubular channels and the second evaporation pot.
5. The refrigeration system of claim 1 , further comprising a dilution refrigerator that is thermally coupled to the first and the second evaporation pots.
6. The refrigeration system of claim 5 , further comprising a superconducting processor that is thermally coupled to the dilution refrigerator.
7. The refrigeration system of claim 6 wherein the superconducting processor includes a superconducting quantum processor.