Closed-cycle gas flow system for cooling a HTc DC-SQUID magnetometer

P.J. van den Bosch, H.J. Holland, H.J.M. ter Brake, H. Rogalla

    Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review


    A closed-cycle gas flow system for cooling a HTc dc-SQUID magnetometer by means of a cryocooler has been designed, constructed and tested. The magnetometer is aimed to measure heart signals with a sensitivity of 0.1 pT/Hzl/2. The required operating temperature of the SQUID is 30 to 70 K with a stability of 0.5 K. Allowing for a cool-down time of about one hour a cooling power of at least 0.2 W is required (sensor mass ∼ 2 g). Further requirements for the system are a low vibration level and a low magnetic interference. In our design, helium gas is forced to flow in a closed cycle by means of a gas-flow pump. The gas is cooled by a Leybold Heraeus RG 210 cooler, transported through a gas line, and cools the SQUID in a glass-epoxy heat exchanger. The return gas is used to thermally insulate the supply gas. Because the gas-flow pump has to operate at room temperature, a counterflow heat exchanger has been incorporated. Based on the experience with this cooling system, a much smaller configuration using a miniature Stirling cryocooler will be designed. In the paper the design and construction of the present closed-cycle system is described and first test results are presented.
    Original languageEnglish
    Title of host publicationAdvances in Cryogenic Engineering
    Subtitle of host publicationProceedings of the 1993 Cryogenic Engineering Conference, held July 12-16, 1993, in Albuquerque, New Mexico
    EditorsPeter Kittel
    Place of PublicationBoston, MA
    Number of pages9
    ISBN (Electronic)978-1-4615-2522-6
    ISBN (Print)978-1-4613-6074-2
    Publication statusPublished - 1994
    Event1992 Cryogenic Engineering Conference & International Cryogenic Materials Conference, CEC/ICMC 1992 - Kiev, Ukraine
    Duration: 8 Jun 199212 Jun 1992

    Publication series

    NameAdvances in cryogenic engineering
    Volume39, Part A
    ISSN (Print)0065-2482


    Conference1992 Cryogenic Engineering Conference & International Cryogenic Materials Conference, CEC/ICMC 1992
    Abbreviated titleCEC/ICMC


    • Heat exchanger
    • Cooling power
    • Sensor unit
    • Radiation shield
    • Common mode rejection ratio


    Dive into the research topics of 'Closed-cycle gas flow system for cooling a HTc DC-SQUID magnetometer'. Together they form a unique fingerprint.

    Cite this