CUSTOM THERMAL SHIELDS FOR CRYOGENIC ENVIRONMENTS
20220221107 · 2022-07-14
Inventors
- Patryk Gumann (Tarrytown, NY, US)
- Valerio A. Grendanin (St. Augustine, FL, US)
- Sean Hart (Tarrytown, NY, US)
- David C. Mckay (Ossining, NY, US)
- Jerry M. Chow (Scarsdale, NY, US)
- David Zarsky (Bethlehem, PA, US)
- Gilbert Bauer (Peekskill, NY, US)
US classification
- 1/1
Cpc classification
F17C2203/0391 F17C2203/0391
F17C3/085 F17C3/085
F25B9/10 F25B9/10
F25D19/006 F25D19/006
F17C2201/0119 F17C2201/0119
F25D19/00 F25D19/00
F17C2203/0646 F17C2203/0646
International classification
Abstract
Techniques facilitating custom thermal shields for cryogenic environments are provided. In one example, a cryostat can comprise a thermal shield extending between a thermal stage and a base structure coupled to a bottom plate of an outer vacuum chamber. The thermal stage can be coupled to a top plate of the outer vacuum chamber. The thermal shield can provide access to a sample mounting surface encompassed within the thermal shield from a region external to the outer vacuum chamber via the top and bottom plates of the outer vacuum chamber.
Claims
1. A cryostat, comprising: a thermal shield extending between a thermal stage and a base structure coupled to a bottom plate of an outer vacuum chamber, the thermal stage coupled to a top plate of the outer vacuum chamber, the thermal shield providing access to a sample mounting surface encompassed within the thermal shield from a region external to the outer vacuum chamber via the top and bottom plates of the outer vacuum chamber.
2. The cryostat of claim 1, wherein the thermal shield is mechanically coupled to the bottom structure by a flexible structure that intervenes between the thermal shield and the base structure.
3. The cryostat of claim 2, wherein the flexible structure thermally couples the thermal shield to the base structure.
4. The cryostat of claim 2, wherein the flexible structure facilitates vertical movement of the thermal shield with respect to the base structure.
5. The cryostat of claim 1, wherein the thermal stage and the base structure operate at substantially similar temperatures.
6. The cryostat of claim 1, wherein the thermal shield is partitioned into a plurality of sections extending between the thermal stage and the base structure.
7. The cryostat of claim 6, wherein a metal strip extending between the thermal stage and the base structure overlays a seam intervening between adjacent sections among the plurality of sections to minimize radiation of energy from the thermal stage to a lower temperature thermal stage of the cryostat.
8. The cryostat of claim 6, wherein the plurality of sections includes a stationary section and a removable section.
9. The cryostat of claim 1, wherein the thermal shield is mechanically anchored to the thermal stage via a plurality of attachment mechanisms.
10. The cryostat of claim 1, wherein the thermal stage is a 50-kelvin stage or a 4-kelvin stage.
11. The cryostat of claim 1, wherein the thermal shield is a metal cylinder with open ends.
12. The cryostat of claim 1, wherein the thermal shield comprises aluminum, copper, brass, titanium, gold, platinum, or a combination thereof.
13. The cryostat of claim 1, wherein the thermal shield comprises a minimum thickness of an eighth of an inch.
14. A cryostat, comprising: a flexible structure intervening between a thermal shield and a base structure coupled to a bottom plate of an outer vacuum chamber, wherein the flexible structure mechanically couples the thermal shield to the base structure, wherein the thermal shield extends between the base structure and a thermal stage coupled to a top plate of the outer vacuum chamber, and wherein the thermal shield provides access to a sample mounting surface encompassed within the thermal shield from a region external to the outer vacuum chamber via the top and bottom plates of the outer vacuum chamber.
15. The cryostat of claim 14, wherein the flexible structure facilitates vertical movement of the thermal shield with respect to the base structure.
16. The cryostat of claim 14, wherein the thermal stage and the base structure operate at substantially similar temperatures.
17. The cryostat of claim 14, wherein the flexible structure thermally couples the thermal shield to the base structure, and wherein a plurality of attachment mechanisms mechanically anchoring the thermal shield to the thermal stage facilitate thermally coupling the thermal shield with the thermal stage.
18. The cryostat of claim 14, wherein the flexible structure comprises aluminum, copper, brass, titanium, gold, platinum, or a combination thereof.
19. The cryostat of claim 14, wherein the flexible structure couples with the base structure on a first side of the thermal shield and couples with the thermal shield on a second side of the thermal shield that opposes the first side.
20. The cryostat of claim 14, wherein the flexible structure comprises a foil or a braided metal wire.
21. The cryostat of claim 14, wherein the flexible structure comprises a slack defined by a maximum vertical displacement of the thermal shield responsive to varying geometries of the thermal stage due to thermal expansion or contraction.
22. A cryostat comprising: a base structure coupled to a bottom plate of an outer vacuum chamber and a flexible structure intervening between the base structure and a thermal shield, wherein the flexible structure mechanically couples the base structure to the thermal shield, wherein the thermal shield extends between the base structure and a thermal stage coupled to a top plate of the outer vacuum chamber, and wherein the thermal shield provides access to a sample mounting surface encompassed within the thermal shield from a region external to the outer vacuum chamber via the top and bottom plates of the outer vacuum chamber.
23. The cryostat of claim 22, wherein the base structure comprises a clearance hole for receiving an attachment mechanism that couples the base structure to the flexible structure.
24. The cryostat of claim 22, wherein the flexible structure facilitates vertical movement of the thermal shield with respect to the base structure.
25. The cryostat of claim 22, wherein the flexible structure thermally couples the base structure with the thermal stage.
Description
DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0036] The following detailed description is merely illustrative and is not intended to limit embodiments and/or application or uses of embodiments. Furthermore, there is no intention to be bound by any expressed or implied information presented in the preceding Background or Summary sections, or in the Detailed Description section.
[0037] One or more embodiments are now described with reference to the drawings, wherein like referenced numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a more thorough understanding of the one or more embodiments. It is evident, however, in various cases, that the one or more embodiments can be practiced without these specific details.
[0038]
[0039] Each stage among the plurality of stages 140 can be associated with a different temperature. For example, stage 141 can be a 50-kelvin (50-K) stage that is associated with a temperature of 50 kelvin (K), stage 143 can be a 4-kelvin (4-K) stage that is associated with a temperature of 4 K, stage 145 can be associated with a temperature of 700 millikelvin (mK), stage 147 can be associated with a temperature of 100 mK, and stage 149 can be associated with a temperature of 10 mK. In an embodiment, stage 145 can be a Still stage, stage 147 can be a Cold Plate stage, and stage 149 can be a Mixing Chamber stage. One or more support rods (e.g., support rod 142) can couple the plurality of stages 140 to top plate 114 of outer vacuum chamber 110. Moreover, each stage among the plurality of stages 140 can be spatially isolated from other stages of the plurality of stages 140 by a plurality of support rods (e.g., support rod 144). In an embodiment, support rods 142 and/or 144 can comprise stainless steel.
[0040] As shown by
[0041]
[0042] Thermal shield 210 can comprise a metal strip 220 extending between stage 141 and base structure 160. Metal strip 220 can overlay a seam or gap intervening between adjacent sections of thermal shield 210. For example, a side edge 312 of section 212 and a side edge 316 of section 216 can define a seam or gap between sections 212 and 216. In this example, the seam or gap between sections 212 and 216 can arise due to machining tolerances associated with manufacturing sections 212 and 216. As shown by
[0043]
[0044] With reference to
[0045] In various embodiments, thermal shield 410 can be partitioned into multiple sections to facilitate modularity in implementing thermal shield 410. By way of example,
[0046] In an embodiment, the multiple sections of thermal shield 410 can include a stationary section and a removeable section. In this embodiment, the stationary section can be permanently or semi-permanently coupled (e.g., welded) to a frame structure associated with the outer vacuum chamber comprising top and bottom plates 510 and 520. Permanently or semi-permanently coupling the stationary section to the frame structure can extend a time for removal of the stationary section from cryostat 400. In this embodiment, the removeable section can be impermanently coupled (e.g., via attachment mechanisms, such as bolts and/or screws) to the frame structure. Impermanently coupling the removeable section to the frame structure can reduce a time for removal of the removeable section from cryostat 400 to facilitate quick access to components encompassed within thermal shield 410.
[0047] As shown by
[0048] In this example, top plate 510 and thermal stage 530 can intervene between feedthrough port 422 and exterior region 505. As such, top plate 510 and thermal stage 530 can represent obstructions for routing line 440 between exterior region 505 and sample mounting surface 430. To mitigate such obstructions, top plate 510 and thermal stage 530 can include feedthrough ports 512 and 532, respectively, that align with feedthrough port 422. In contrast, the routing of line 440 between exterior region 505 and sample mounting surface 430 is unobstructed by thermal shield 410. Therefore, thermal shield 410 lacks feedthrough ports for routing line 440 between exterior region 505 and sample mounting surface 430.
[0049] Similarly, bottom plate 520 and base structure 540 intervene between feedthrough port 424 and exterior region 505 in this example. As such, bottom plate 520 and base structure 540 can represent obstructions for routing line 450 between exterior region 505 and sample mounting surface 430. To mitigate such obstructions, bottom plate 520 and base structure 540 can include feedthrough ports 522 and 542, respectively, that align with feedthrough port 424. In contrast, the routing of line 450 between exterior region 505 and sample mounting surface 430 is again unobstructed by thermal shield 410. Therefore, thermal shield 410 lacks feedthrough ports for routing line 450 between exterior region 505 and sample mounting surface 430. By providing unobstructed routing for input/output lines between exterior region 505 and sample mounting surface 430 via both top plate 510 and bottom plate 520, thermal shield 410 can facilitate accommodating an increased number of input/output lines.
[0050] Thermal shield 410 can extend between thermal stage 530 and base structure 540. In an embodiment, thermal stage 530 can be a 50-K stage, a 4-K stage, a Still stage, a Cold Plate state, or a Mixing Chamber stage. In an embodiment, thermal stage 530 and base structure 540 can operate at substantially similar temperatures. For example, if thermal stage 530 is a 4-K stage, base structure 540 can operate at a temperature of approximately 4 K. As thermal shield 410 extends between thermal stage 530 and base structure 540, a thermal gradient can develop within thermal shield 410. To facilitate minimizing such thermal gradients, thermal shield 410 can be thermally coupled with thermal stage 530 and base structure 540.
[0051] Mechanically coupling thermal shield 410 with thermal stage 530 and base structure 540 can facilitate thermally coupling thermal shield 410 with thermal stage 530 and base structure 540. However, one skilled in the art will recognize that geometries of thermal stage 530 and base structure 540 can vary as respective temperatures of thermal stage 530 and base structure 540 change due to thermal expansion/contraction. Moreover, the respective geometries of thermal stage 530 and base structure 540 can vary at different rates, directions, and/or magnitudes. Therefore, mechanically coupling thermal shield 410 with thermal stage 530 and base structure 540 in a rigid manner can negatively impact a structural integrity of thermal shield 410. Accordingly, providing some flexibility in the mechanical coupling of thermal shield 410 with thermal stage 530 and base structure 540 can facilitate preserving a structure integrity of thermal shield 410.
[0052] As shown by
[0053]
[0054] By operation of flexible structure 630 such vertical movement imparted on thermal shield 410 can translate into vertical displacement between thermal stage 530 and base structure 540 instead of negatively impacting a structural integrity of thermal shield 410. As shown by
[0055] Flexible structure 630 can comprise slack or excess to accommodate for such increased and/or decreased vertical displacement between thermal stage 530 and base structure 540. In an embodiment, the slack or excess of flexible structure 630 can be defined by a maximum vertical displacement of thermal shield 410 responsive to varying geometries of thermal stage 530 due to thermal expansion or contraction. In an embodiment, the maximum vertical displacement of thermal shield 410 can be determined using a maximum increase in vertical displacement (e.g., increase vertical displacement 710) between thermal stage 530 and base structure 540. In an embodiment, the maximum vertical displacement of thermal shield 410 can be determined using a maximum decrease in vertical displacement (e.g., decrease vertical displacement 810) between thermal stage 530 and base structure 540.
[0056]
[0057] As shown by
[0058] In an embodiment, a thermal shield (e.g., thermal shields 210 and/or 410) can be a metal cylinder with open ends. In this embodiment, the thermal shield can comprise a circumference in which each section can be curved to provide an arc of the circumference. Minimizing gaps between metal strip 905 and such curved sections can involve transitioning metal strip 905 from the flat state shown by
[0059]
[0060] Each clearance hole among the plurality of clearance holes 1410 can receive an attachment mechanism (e.g., a bolt or a screw) to mechanically anchor section 1405 to a thermal stage (e.g., stages 141 or 143 of
[0061] In an embodiment, a thermal shield (e.g., thermal shields 210 and/or 410) comprising section 1405 can be a metal cylinder with open ends. In an embodiment, one open end of the metal cylinder can circumscribe an outer wall of the thermal stage when the thermal shield is mechanically anchored to the thermal stage. In an embodiment, the thermal shield can comprise a circumference in which each section can be curved to provide an arc of the circumference. Minimizing gaps between section 1405 and the outer wall of the thermal stage can involve transitioning section 1405 from the flat state shown by
[0062]
[0063] Each clearance hole among the plurality of clearance holes 1910 can receive an attachment mechanism (e.g., a bolt or a screw) to mechanically anchor section 1905 to a thermal stage (e.g., stages 141 or 143 of
[0064] In an embodiment, a thermal shield (e.g., thermal shields 210 and/or 410) comprising section 1905 can be a metal cylinder with open ends. In an embodiment, one open end of the metal cylinder can circumscribe an outer wall of the thermal stage when the thermal shield is mechanically anchored to the thermal stage. In an embodiment, the thermal shield can comprise a circumference in which each section can be curved to provide an arc of the circumference. Minimizing gaps between section 1905 and the outer wall of the thermal stage can involve transitioning section 1905 from the flat state shown by
[0065] Embodiments of the present invention may be a system, a method, and/or an apparatus at any possible technical detail level of integration. What has been described above includes mere examples of systems, methods, and apparatus. It is, of course, not possible to describe every conceivable combination of components or computer-implemented methods for purposes of describing this disclosure, but one of ordinary skill in the art can recognize that many further combinations and permutations of this disclosure are possible. Furthermore, to the extent that the terms “includes,” “has,” “possesses,” and the like are used in the detailed description, claims, appendices and drawings such terms are intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.
[0066] In addition, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from context, “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then “X employs A or B” is satisfied under any of the foregoing instances. Moreover, articles “a” and “an” as used in the subject specification and annexed drawings should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form. As used herein, the terms “example” and/or “exemplary” are utilized to mean serving as an example, instance, or illustration. For the avoidance of doubt, the subject matter disclosed herein is not limited by such examples. In addition, any aspect or design described herein as an “example” and/or “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art.
[0067] The descriptions of the various embodiments have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
[0068] While certain example embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope the disclosures herein. Thus, nothing in the foregoing description is intended to imply that any particular feature, characteristic, step, module, or block is necessary or indispensable. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosures herein. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of certain of the disclosures herein.