Systems and methods for cryogenic refrigeration
Assignee1372934 B.C. Ltd.
InventorsJacob Craig Petroff, Richard G. Harris
Life of this patent
Estimating the term…
Abstract
Systems and methods for improving the performance of dilution refrigeration systems are described. Filters and traps employed in the helium circuit of a dilution refrigerator may be modified to improve performance. Some traps may be designed to harness cryocondensation as opposed to cryoadsorption. A cryocondensation trap employs a cryocondensation surface having a high thermal conductivity and a high specific heat with a binding energy that preferably matches at least one contaminant but does not match helium. Multiple traps may be coupled in series in the helium circuit, with each trap designed to trap a specific contaminant or set of contaminants. Both cryocondensation and cryoadsorption may be exploited among multiple traps.
Claims14
A cryogenic trapping system comprising:
- a helium fluid circuit;
- a pulse tube cryocooler comprising a first temperature stage and a second temperature stage, the first temperature stage operating at a first temperature and the second temperature stage operating at a second temperature that is less than the first temperature;
- a first trapping subsystem incorporated into the helium fluid circuit, the first trapping subsystem comprising first and second contaminant traps arranged in parallel and selectively thermally coupled to the first temperature stage of the pulse tube cryocooler by respective first and second heat switches, the first and second heat switches providing controllable thermal coupling between the first and second contaminant traps and the first temperature stage of the pulse tube cryocooler;
- a cryoadsorptive trap incorporated into the helium fluid circuit in series with the first trapping subsystem, the cryoadsorptive trap thermally coupled to the second temperature stage of the pulse tube cryocooler, the cryoadsorptive trap comprising:
- a plurality of thermalization surfaces arranged to define a circuitous flow route through the cryoadsorptive trap;
- and
- an adsorption material arranged along the circuitous flow route;
- and
- a cryocondensation trap incorporated into the helium fluid circuit in series with the cryoadsorptive trap, the cryocondensation trap comprising a trapping surface, the cryocondensation trap thermally coupled to the second temperature stage of the pulse tube cryocooler.
Dependencies are inferred from the claim text.