A heart scanner that can be equipped with up to 25 high-Tc SQUID magnetometers was designed at the University of Twente. In this design the mechanical cooler interference is reduced by operating two coolers in counterphase. The magnetic cooler interference diminished by positioning the coolers and the SQUIDs in a coplanar arrangement, and by separating the SQUIDs from the cold tips of the cryocoolers with a solid conducting thermal interface.

    In the present paper the construction of this cryogen-free high-Tc SQUID system is described and test results are presented. A SQUID plate temperature of 60 K was realized in about 2 hours. The corresponding heat load to the coolers is roughly 0.9 W. With a preliminary magnetic shield around the compressors a noise level of 0.6 pT/√Hz was measured in the frequency band 10 to 100 Hz and magnetocardiograms were recorded inside a magnetically shielded room. A further reduction of the noise level is expected after optimizing the mumetal shielding of the compressors.


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    Title :

    Construction and Tests of a High-Tc SQUID-Based Heart Scanner Cooled by Small Stirling Cryocoolers


    Contributors:

    Published in:

    Cryocoolers 10 ; Chapter : 99 ; 837-846


    Publication date :

    2002-01-01


    Size :

    10 pages




    Type of media :

    Article/Chapter (Book)


    Type of material :

    Electronic Resource


    Language :

    English




    Construction and Tests of a High-Tc SQUID-Based Heart Scanner Cooled by Small Stirling Cryocoolers

    Blom, C. J. H. A. / ter Brake, H. J. M. / Holland, H. J. et al. | British Library Conference Proceedings | 1999


    Numerical Modeling of Stirling Cryocoolers

    Bauwens, L. / AIAA | British Library Conference Proceedings | 1994


    Numerical Modeling of Stirling Cryocoolers

    Bauwens, L. / AIAA | British Library Conference Proceedings | 1994



    Reduction of the Vibration Generated by Stirling Cryocoolers Used for Cooling a High-Tc SQUID Magnetometer

    Verberne, J. F. C. / Bruins, P. C. / Van den Bosch, P. J. et al. | British Library Conference Proceedings | 1995