EP0053784B1 - Cryostat combiné avec une machine frigorifique - Google Patents

Cryostat combiné avec une machine frigorifique Download PDF

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Publication number
EP0053784B1
EP0053784B1 EP81110025A EP81110025A EP0053784B1 EP 0053784 B1 EP0053784 B1 EP 0053784B1 EP 81110025 A EP81110025 A EP 81110025A EP 81110025 A EP81110025 A EP 81110025A EP 0053784 B1 EP0053784 B1 EP 0053784B1
Authority
EP
European Patent Office
Prior art keywords
stage
refrigerator
pump
cold head
pump face
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.)
Expired
Application number
EP81110025A
Other languages
German (de)
English (en)
Other versions
EP0053784A1 (fr
Inventor
Hans-Joachim Dr. Forth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Balzers und Leybold Deutschland Holding AG
Original Assignee
Leybold Heraeus GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Leybold Heraeus GmbH filed Critical Leybold Heraeus GmbH
Publication of EP0053784A1 publication Critical patent/EP0053784A1/fr
Application granted granted Critical
Publication of EP0053784B1 publication Critical patent/EP0053784B1/fr
Expired legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
    • F04B37/06—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for evacuating by thermal means
    • F04B37/08—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for evacuating by thermal means by condensing or freezing, e.g. cryogenic pumps

Definitions

  • two-stage refrigerators of this type and helium as the working gas e.g. B. generate temperatures below 10 K.
  • the second stage of the refrigerator cold head cools the sample and the first stage radiation protection which surrounds the second stage with the sample held thereon as completely as possible.
  • the reproducible setting of any temperatures in the range from 10 K to about 350 K on the sample is achieved by appropriate electrical heating of the second stage.
  • the pressure in the housing of the cryostat small 10- 3 must be mbar.
  • a high vacuum pump (diffusion pump, turbomolecular pump or ion atomizing pump) is generally used to generate and maintain this insulating vacuum.
  • backing pumps are essential for the operation of these pumps. This relatively high outlay for vacuum generation in the cryostat housing is also necessary, among other things, so that gases evaporating from the sample and / or from the second stage of the refrigerator at higher temperatures do not accumulate again on the sample and contaminate it when the temperature of the sample is restored is lowered.
  • the present invention has for its object to provide a refrigerator cryostat with a two-stage cold head, in which a complex system for generating the insulating vacuum can be dispensed with, without the risk of contamination of the cooled sample.
  • this object is achieved in that the first stage of the cold head of the refrigerator is equipped with a pump surface.
  • This pumping surface acts as a cryo-condensation and / or as a cryo-sorption pump, so that the external high-vacuum pump can be dispensed with. It is sufficient if a mechanical vacuum pump is available for pre-evacuation.
  • the second cold stage expediently serves to hold the sample and to set variable low temperatures, while the first cold stage is equipped with the pump surface.
  • the first stage of a refrigerator generally assumes an essentially constant temperature of 40 to 60 K during operation, regardless of the temperature of the second stage. At this temperature, gases such as CH 4 , N 2 , etc. can be bound to the pump surface by sorption. This enables pressures in the 10-5 mbar range to be maintained.
  • a refrigerator cryostat 1 with a two-stage refrigerator which is accommodated in a housing, was chosen as the exemplary embodiment.
  • Known drive devices for the refrigerator cold head are accommodated in the lower part 3 of the housing in a manner not shown in detail. They are supplied with power via the connecting cable 4.
  • the connecting pieces 5 and 6 are also provided for the supply and discharge of the working gas.
  • the lower housing part carries a temperature display 7 for the temperature of the second stage.
  • the actual two-stage cold head 10 of the refrigerator is located in the housing parts 8 and 13.
  • the first stage 9 of the cold head 10 of the refrigerator is located in the middle housing part, designated 8.
  • the embodiment is shown as a section.
  • the cylindrical sections 11 and 12 of the cold head 10 of the refrigerator are visible, in which the displacers of the first and second stages of the two-stage refrigerator are located.
  • the upper part 13 of the cryostat housing is shown closed again.
  • the second stage of the refrigerator is located in this area, on which the sample is held in a manner that is not known and is known per se.
  • the housing part 13 is provided with removable stars 14 so that the sample can be observed on the one hand.
  • the visible first stage 9 of the refrigerator has a flange 16 on which a further flange 17 is fastened, which carries a cylindrical shield 18 for the sample.
  • the first stage 9 of the refrigerator is equipped with a pump surface 19, which consists essentially of a cylindrically shaped copper sheet, which is also fastened to the flange 16 via four bent tabs 20, so that there is good thermal contact with the first stage.
  • the pump surface 19 is nickel-plated on the outside and coated with several grams of activated carbon on the inside towards the first stage.
  • the outside of the sheet serves as a cryocondensation pump and the inside serves as a cryosorption pump.
  • Fig. 2 the pump surface 19 is suit again shown wraps.
  • the sheet is coated on one side with activated carbon.
  • the length of the tabs 20 is selected so that there are openings for the passage of the gases between the outer edge of the flange 16 and the cylindrical section.
  • the first stage 9 of the refrigerator is additionally equipped with a heating sleeve 21. This heating is only switched on when it is necessary to regenerate the sorption surfaces.
  • the heating energy is supplied in a manner which is not shown in more detail via a vacuum-tight electrical feedthrough designated 22.
  • This implementation also supplies the invisible second stage with heating current in a manner known per se in order to be able to set the temperature of the sample to the desired values.
  • the connecting piece 23 on the central housing part 8 is only connected to a fore-vacuum pump 24. This only serves to pre-evacuate the housing before and during cooling of the refrigerator. It can be separated from the housing when the pressure falls below about 10- 2 mbar after cooling the refrigerator cold head.
  • the sorption surface 19 then has the effect that pressures in the 10-5 mbar range can be generated and maintained. Even if higher temperatures are set at the second stage of up to 350 K, the pressure in the housing always remains at sufficiently low values. How long this low pressure can be maintained depends on the capacity of the activated carbon.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Claims (5)

1. Cryostat à machine frigorifique (1) comprenant une tête froide (10) à deux étages agencée dans une enveloppe (8, 13) et dont le deuxième sert à fixer une sonde et à la mettre à bonne température, et peut être réglé à des températures variables par un chauffage électrique approprié, caractérisé en ce que le premier étage (9) de la tête froide (10) est équipé d'une surface de pompage (19).
2. Cryostat à machine frigorifique selon la revendication 1, caractérisée en ce que la surface de pompage (19) est formée d'un segment de tôle façonné à une forme cylindrique.
3. Cryostat à machine frigorifique selon la revendication 2, caractérisé en ce que la surface de pompage (19) est reliée au premier étage de la tête froide (10) par l'intermédiaire de pattes coudées (20).
4. Cryostat à machine frigorigique selon la revendication 2 ou 3, caractérisé en ce que la surface de pompage (19) est constituée par une tôle de cuivre qui est extérieurement nickelée à nickelage très brillant et revêtue intérieurement de charbon actif.
5. Cryostat à machine frigorifique selon l'une des revendications précédentes, caractérisé en ce qu'un dispositif de chauffage (21) est agencé dans la région de la surface de pompage (19).
EP81110025A 1980-12-10 1981-12-01 Cryostat combiné avec une machine frigorifique Expired EP0053784B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19803046458 DE3046458A1 (de) 1980-12-10 1980-12-10 Refrigerator-kryostat
DE3046458 1980-12-10

Publications (2)

Publication Number Publication Date
EP0053784A1 EP0053784A1 (fr) 1982-06-16
EP0053784B1 true EP0053784B1 (fr) 1984-08-08

Family

ID=6118758

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81110025A Expired EP0053784B1 (fr) 1980-12-10 1981-12-01 Cryostat combiné avec une machine frigorifique

Country Status (3)

Country Link
US (1) US4408469A (fr)
EP (1) EP0053784B1 (fr)
DE (1) DE3046458A1 (fr)

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2115602B (en) * 1982-02-24 1986-01-02 Philips Electronic Associated Getters in infra-red radiation detectors
FR2572794B1 (fr) * 1984-11-06 1987-06-12 Commissariat Energie Atomique Procede pour augmenter la capacite d'absorption d'une pompe de cryopompage et pompe de cryopompage associee
US4719938A (en) * 1985-01-22 1988-01-19 Helix Technology Corporation Self-cleaning valve and cryopump utilizing the same
US4763483A (en) * 1986-07-17 1988-08-16 Helix Technology Corporation Cryopump and method of starting the cryopump
US5001903A (en) * 1987-01-27 1991-03-26 Helix Technology Corporation Optimally staged cryopump
EP0349577B1 (fr) * 1987-01-27 1994-11-30 Helix Technology Corporation Cryopompe a etagement optimal
DE3836884C2 (de) * 1988-10-29 1997-10-02 Leybold Ag Verfahren zur Untersuchung einer auf dem Kaltkopf eines Kryostaten befindlichen Probe und Refrigerator-Kryostat
DE3943772C2 (de) * 1988-11-09 1998-01-02 Mitsubishi Electric Corp Mehrstufige Gaskältemaschine
US5251456A (en) * 1988-11-09 1993-10-12 Mitsubishi Denki Kabushiki Kaisha Multi-stage cold accumulation type refrigerator and cooling device including the same
US5144810A (en) * 1988-11-09 1992-09-08 Mitsubishi Denki Kabushiki Kaisha Multi-stage cold accumulation type refrigerator and cooling device including the same
US5092130A (en) * 1988-11-09 1992-03-03 Mitsubishi Denki Kabushiki Kaisha Multi-stage cold accumulation type refrigerator and cooling device including the same
US5293752A (en) * 1988-11-09 1994-03-15 Mitsubishi Denki Kabushiki Kaisha Multi-stage cold accumulation type refrigerator and cooling device including the same
DE3936914C2 (de) * 1988-11-09 1996-06-27 Mitsubishi Electric Corp Mehrstufige Gaskältemaschine
US5144805A (en) * 1988-11-09 1992-09-08 Mitsubishi Denki Kabushiki Kaisha Multi-stage cold accumulation type refrigerator and cooling device including the same
USRE36610E (en) * 1989-05-09 2000-03-14 Kabushiki Kaisha Toshiba Evacuation apparatus and evacuation method
DE4336035A1 (de) * 1993-10-22 1995-04-27 Leybold Ag Verfahren zum Betrieb einer Kryopumpe sowie Vakuumpumpensystem mit Kryopumpe und Vorpumpe
US5857342A (en) * 1998-02-10 1999-01-12 Superconductor Technologies, Inc. Temperature controlling cryogenic package system
US7293426B2 (en) * 2004-10-05 2007-11-13 Washington University Apparatus for freezing a biological sample
US20110283737A1 (en) * 2010-05-20 2011-11-24 Siemens Medical Solutions Usa, Inc. Process for separating gases at cryogenic temperatures
EP2458218A1 (fr) 2010-11-30 2012-05-30 Converteam Technology Ltd Système de maintenance d'un vide poussé

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3390536A (en) * 1967-02-01 1968-07-02 Gca Corp Cryogenic pumping apparatus
FR1603997A (en) * 1968-12-27 1971-06-21 Low temperature sorption pump
DE2536005A1 (de) * 1975-08-13 1977-02-24 Eckhard Kellner Hochvakuum-pumpensystem
DE2455712A1 (de) * 1974-11-25 1976-08-12 Eckhard Kellner Cryo-sorptionspumpe
US4150549A (en) * 1977-05-16 1979-04-24 Air Products And Chemicals, Inc. Cryopumping method and apparatus
FR2396879A1 (fr) * 1977-07-05 1979-02-02 Air Liquide Cryopompe
DE2736491C2 (de) * 1977-08-12 1986-04-30 Linde Ag, 6200 Wiesbaden Verfahren zum Evakuieren eines Vakuumbehälters für eine Verflüssigungsanlage für tiefsiedende Gase
US4143520A (en) * 1977-12-23 1979-03-13 The United States Of America As Represented By The Secretary Of The Navy Cryogenic refrigeration system
CH628959A5 (en) * 1978-04-18 1982-03-31 Balzers Hochvakuum Cryopump with a fitted refrigerating machine
DE2830943C2 (de) * 1978-07-14 1986-06-12 Leybold-Heraeus GmbH, 5000 Köln Kryopumpenanordnung
US4295338A (en) * 1979-10-18 1981-10-20 Varian Associates, Inc. Cryogenic pumping apparatus with replaceable pumping surface elements
US4311018A (en) * 1979-12-17 1982-01-19 Varian Associates, Inc. Cryogenic pump

Also Published As

Publication number Publication date
EP0053784A1 (fr) 1982-06-16
US4408469A (en) 1983-10-11
DE3046458A1 (de) 1982-07-15

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