GB2282437A - Vibration damped dilution refrigerator - Google Patents
Vibration damped dilution refrigerator Download PDFInfo
- Publication number
- GB2282437A GB2282437A GB9319593A GB9319593A GB2282437A GB 2282437 A GB2282437 A GB 2282437A GB 9319593 A GB9319593 A GB 9319593A GB 9319593 A GB9319593 A GB 9319593A GB 2282437 A GB2282437 A GB 2282437A
- Authority
- GB
- United Kingdom
- Prior art keywords
- chamber
- insert
- dilution refrigerator
- refrigerator according
- sleeve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000010790 dilution Methods 0.000 title claims abstract description 22
- 239000012895 dilution Substances 0.000 title claims abstract description 22
- 238000013016 damping Methods 0.000 claims abstract description 13
- 239000012530 fluid Substances 0.000 claims abstract description 6
- 238000012360 testing method Methods 0.000 claims description 15
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- 229920001971 elastomer Polymers 0.000 claims description 5
- 229910052734 helium Inorganic materials 0.000 claims description 5
- 239000007788 liquid Substances 0.000 claims description 5
- 239000000806 elastomer Substances 0.000 claims description 4
- 239000001307 helium Substances 0.000 claims description 4
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 4
- 230000005641 tunneling Effects 0.000 claims description 3
- 239000004411 aluminium Substances 0.000 claims description 2
- 229910052782 aluminium Inorganic materials 0.000 claims description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 2
- 230000008878 coupling Effects 0.000 claims description 2
- 238000010168 coupling process Methods 0.000 claims description 2
- 238000005859 coupling reaction Methods 0.000 claims description 2
- 230000005672 electromagnetic field Effects 0.000 claims description 2
- 238000002955 isolation Methods 0.000 claims description 2
- 230000002093 peripheral effect Effects 0.000 claims 1
- 238000005057 refrigeration Methods 0.000 claims 1
- 239000000463 material Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 229920002449 FKM Polymers 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000013536 elastomeric material Substances 0.000 description 1
- 239000011152 fibreglass Substances 0.000 description 1
- GWUAFYNDGVNXRS-UHFFFAOYSA-N helium;molecular oxygen Chemical compound [He].O=O GWUAFYNDGVNXRS-UHFFFAOYSA-N 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000004073 vulcanization Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y15/00—Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
- F25B9/12—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point using 3He-4He dilution
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
- F25D19/00—Arrangement or mounting of refrigeration units with respect to devices or objects to be refrigerated, e.g. infrared detectors
- F25D19/006—Thermal coupling structure or interface
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Nanotechnology (AREA)
- General Engineering & Computer Science (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Molecular Biology (AREA)
- Crystallography & Structural Chemistry (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Combustion & Propulsion (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
A dilution refrigerator comprises a chamber that receives a cryogenic fluid, an opening in the chamber, an elongate insert (7) that carries a housing 5 which contains apparatus (4) to be tested within the chamber. The insert extends into the chamber through the opening and a sleeve (10) surrounds the insert. The sleeve is adapted to be slidingly and sealingly received in the opening and to permit the insert to be removed from the chamber. A vibration damping arrangement (14) resiliently couples the insert to the sleeve. <IMAGE>
Description
VIBRATION DAMPED DILUTION REFRIGERATOR
DESCRIPTION
This invention relates to a vibration damped dilution refrigerator having particular but not exclusive application for testing apparatus such as a scanning tunneling microscope at cryogenic temperatures.
In order for a scanning tunneling microscope (STM) to resolve features on the scale of a single atom, the microscope needs to be isolated from its surroundings by a damping structure. Hitherto, one component part of this has been achieved by interleaved stacks of metal plates and rubber, which act as a series array of springs, masses and parallel connected dampers. The vibrations are progressively damped as they travel along the chain so as to be of a sufficiently small amplitude at the STM, not to impair its operation.
Whilst such an arrangement operates satisfactorily at room temperatures, if it is desired to cool the STM towards absolute zero, in a dilution refrigerator, the elastomeric material looses its resilient properties.
The present invention provides a solution to this problem.
In accordance with the invention, there is provided a dilution refrigerator comprising a chamber to receive a cryogenic fluid; an opening in the chamber; an elongate insert for receiving at one end thereof a housing that contains apparatus to be tested within the chamber, the insert extending into the chamber through the opening; a sleeve surrounding the insert, the sleeve being adapted to be slidingly and sealingly received in the opening and to permit the insert to be removed from the chamber therethrough; and vibration damping means resiliently coupling the insert to the sleeve.
The present invention thus provides vibration damping means which can be mounted away from the cryogenic fluid, so as to retain its resiliency, and can be provided as a simple modification to an existing dilution refrigerator.
Conveniently, the vibration damping means comprises alternating rings of an elastomer and a metal through which the insert extends.
In order that the invention may be more fully understood an embodiment thereof will now be described by way of example with reference to the accompanying drawings, in which:
Figure 1 is a schematic sectional view of a prior art dilution refrigerator;
Figure 2 corresponds to Figure 1 and additionally shows the improved vibration damping means provided in accordance with the invention; and
Figure 3 is an enlarged sectional view of the vibration damping means of Figure 2.
Referring firstly to Figure 1, a schematic sectional view of a conventional dilution refrigerator is shown, for example as manufactured by Oxford Instruments. The device consists of a cryogenic chamber 1 which receives liquid helium 2 as a cryogenic fluid, at a temperature of 4.2 K. The chamber 1 includes an upper opening 3 through which apparatus under test 4 can be inserted into the cryogenic fluid 2. The chamber 1 includes an electromagnet (not shown) that surrounds the apparatus under test so as to provide an electromagnetic field to be applied to the apparatus 4, for testing purposes.
The apparatus 4 under test is mounted within a housing 5 that defines a vacuum chamber, on a "fridge" 6 which is operative to maintain the apparatus under test 4 at a predetermined temperature. For example, the fridge 6 may comprise an Oxford Instruments "Kelvinox" device which produces a controlled temperature of 7mK by boiling He3 from a 13% He3 - 87% He mixture.
Alternatively, an Oxford Instruments "Heliox" He3 system can be used for the fridge 6, which produces a controlled temperature of 300mK, by pumping on He3 liquid.
The arrangement 4, 5, 6 is mounted on an insert 7 which may comprise an elongate cylindrical member or a series of spaced generally parallel conduits 9 that are connected to a transverse generally circular top plate 8. The conduits extend through the top plate 8 to the vacuum housing 5 and are connected to the source of vacuum (not shown). Also, the conduits provide for electrical connections to the apparatus under test and to the fridge 6.
The insert 7 is surrounded by a cylindrical seal 10, typically made of fibreglass material, which is provided with a flange 11 that is bolted at 13 to the plate 8. The cylindrical seal 10, known as the sliding seal, is slidingly received within a circular seal 12 provided in the opening 3 of the chamber 1. The purpose of the sliding seal 10 is to prevent air entering and condensing in the liquid helium 2.
A problem with this prior arrangement is that if it is used to test performance of a STM at liquid helium temperatures, no vibration isolation is provided. In use, the STM needs to be attached by bolts or screws to the fridge 6 and if an elastomeric damping configuration were provided in the housing 5, it would not operate satisfactorily due to the low temperatures.
Furthermore, the length of the insert 7 tends to amplify any vibration.
A solution to this problem is shown in Figure 2. In accordance with the invention, a vibration damping arrangement 14 is provided exteriorily of the chamber 1, namely away from the region of low temperature, and is coupled between the sliding seal 10 and the top plate 8 of the insert 7. The vibration damping arrangement 14 is shown in more detail in Figure 3 and consists of alternating rings of an elastomer 15 and a metal 16. The elastomeric rinas 15 are tvticallv made
of Vitontand the metal rings 16 may be made of aluminium.The upper and lower ends of the arrangement 14 are defined by upper and lower circular flanges 17, 18 which are provided with bolt holes 13a, 13b of a size and spacing that will connect with a conventional plate 8 and flange 11, to enable the arrangement 14 to be retrofitted to an existing dilution refrigerator.
An O-ring 19 is provided in the upper flange 17 to provide an airtight seal against the top plate 8 of the insert. Similarly, the lowermost flange 18 co-operates with an O-ring 20 that is conventionally provided in the flange 11 of the sliding seal.
An airtight seal is maintained between the various rinas 15. 16 for example bv usina a bondina compound or
by vulcanisation of the Viton material to the surrounding metal plates.
Thus, in use, the arrangement 14 provides vibration damping for the insert 7 relative to the sliding seal and hence the chamber 1. The arrangement of alternate rings 15, 16 act as a series array of springs, masses and parallel connected dampers so that any vibration of the chamber 1 tends to be damped as it is transmitted to the apparatus under test through the insert 7.
The arrangement shown in Figures 2 and 3 has particular application to testing circuitry using a STM.
However, other uses may be found for example in connection with atomic force microscopes (AFM).
Since the arrangement 14 can readily be included or removed from the refrigerator, the refrigerator can be used for STM testing and other purposes, at the discretion of the user.
Claims (12)
1. A dilution refrigerator comprising: a chamber to receive a cryogenic fluid; an opening in the chamber; an elongate insert for receiving at one end thereof a housing that contains apparatus to be tested within the chamber, the insert extending into the chamber through the opening; a sleeve surrounding the insert, the sleeve being adapted to be slidingly and sealingly received in the opening and to permit the insert to be removed from the chamber therethrough; and vibration damping means resiliently coupling the insert to the sleeve.
2. A dilution refrigerator according to claim 1, wherein the vibration damping means comprises alternating rings of an elastomer and a metal through which said insert extends.
3. A dilution refriaerator accordina to claim 2.
wherein the rings ot elastomer are tormed ot Vitro
4. A dilution refrigerator according to claim 2 or 3, wherein the rings of metal are formed of aluminium.
5. A dilution refrigerator according to claim 2, 3 or 4, including means providing an airtight seal between said rings.
6. A dilution refrigerator according to any preceding claim wherein the insert extends downwardly into the chamber, and the upper ends of the insert and the sleeve both have peripheral flanges to which said vibration isolation means is coupled.
7. A dilution refrigerator according to any preceding claim including said housing mounted on the insert, the housing defining a vacuum chamber that contains a refrigeration unit and the apparatus under test.
8. A dilution refrigerator according to claim 7 wherein the apparatus under test includes a scanning tunneling microscope.
9. A dilution refrigerator according to claim 7 wherein said apparatus under test comprises an atomic force microscope.
10. A dilution refrigerator according to any preceding claim wherein the chamber contains liquid helium.
11. A dilution refrigerator according to any preceding claim wherein the chamber includes an electromagnet for applying an electromagnetic field to the apparatus under test.
12. A dilution refrigerator substantially as hereinbefore described with reference to Figures 2 and 3 of the accompanying drawings.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9319593A GB2282437A (en) | 1993-09-22 | 1993-09-22 | Vibration damped dilution refrigerator |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9319593A GB2282437A (en) | 1993-09-22 | 1993-09-22 | Vibration damped dilution refrigerator |
Publications (2)
Publication Number | Publication Date |
---|---|
GB9319593D0 GB9319593D0 (en) | 1993-11-10 |
GB2282437A true GB2282437A (en) | 1995-04-05 |
Family
ID=10742374
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB9319593A Withdrawn GB2282437A (en) | 1993-09-22 | 1993-09-22 | Vibration damped dilution refrigerator |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2282437A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL2001755C2 (en) * | 2008-07-03 | 2010-01-05 | Giorgio Frossati | Holder for a preparation to be cooled to a low temperature in a vacuum space and a 3-he-4 th mixing cooling machine adapted to receive such a holder. |
CN104848575A (en) * | 2014-02-17 | 2015-08-19 | 住友重机械工业株式会社 | Cryogenic refrigerator |
US20230010758A1 (en) * | 2021-07-08 | 2023-01-12 | Maybell Quantum Industries, Inc. | Integrated dilution refrigerators |
CN117287866A (en) * | 2023-11-24 | 2023-12-26 | 中国科学技术大学 | Thermal switch and dilution refrigerator |
-
1993
- 1993-09-22 GB GB9319593A patent/GB2282437A/en not_active Withdrawn
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL2001755C2 (en) * | 2008-07-03 | 2010-01-05 | Giorgio Frossati | Holder for a preparation to be cooled to a low temperature in a vacuum space and a 3-he-4 th mixing cooling machine adapted to receive such a holder. |
WO2010002245A3 (en) * | 2008-07-03 | 2010-03-11 | Giorgio Frossati | Holder for a sample to be cooled to a low temperature in a vacuum space and 3he-4he dilution refrigerator adapted to accommodate such a holder |
US9528744B2 (en) | 2008-07-03 | 2016-12-27 | Giorgio Frossati | Holder for a sample to be cooled to a low temperature in a vacuum space and 3He—4He dilution refrigerator adapted to accommodate such a holder |
CN104848575A (en) * | 2014-02-17 | 2015-08-19 | 住友重机械工业株式会社 | Cryogenic refrigerator |
US20230010758A1 (en) * | 2021-07-08 | 2023-01-12 | Maybell Quantum Industries, Inc. | Integrated dilution refrigerators |
US11946680B2 (en) | 2021-07-08 | 2024-04-02 | Maybell Quantum Industries, Inc. | Integrated dilution refrigerators |
US12000640B2 (en) | 2021-07-08 | 2024-06-04 | Maybell Quantum Industries, Inc. | Integrated dilution refrigerators |
CN117287866A (en) * | 2023-11-24 | 2023-12-26 | 中国科学技术大学 | Thermal switch and dilution refrigerator |
CN117287866B (en) * | 2023-11-24 | 2024-02-09 | 中国科学技术大学 | Thermal switch and dilution refrigerator |
Also Published As
Publication number | Publication date |
---|---|
GB9319593D0 (en) | 1993-11-10 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |