Abstract Advances in regenerator reliability, as well as material cost reduction, can be obtained by optimizing the geometry of the regenerator material. This ongoing development effort for <10K Gifford-McMahon (G-M) refrigerators utilizes coiled ribbons of Neodymium (Nd) instead of the typical spheroidal powder. The ribbons, which have small ridges on one face, are coiled to form flat pancakes. The height of the ridge in relation to the thickness of the tape determines the void volume. These flat coils are then stacked to form a cylinder and packed into the second stage of a G-M refrigerator, in the place of the Nd spheres. This paper describes the fabrication process used to create ribbons from the Nd rare-earth material. Although easier to fabricate than intermetallic regenerator materials, Nd work-hardens and oxidizes rapidly. Modifications were made to conventional extrusion, drawing and rolling processes to overcome these difficulties. The production process developed has much greater yields (>80%) than current Nd powder atomization techniques, which yields only 15% to 30%. Test results show that the amount of void volume, and therefore the pressure drop, can easily be controlled and optimized by varying the ribbon geometry. Whereas the void volume of packed Nd powder is normally roughly 35%, ribbon geometries with void volumes of 15% and 20%, were manufactured and tested. Current efforts are described to further improve the geometry and increase cryogenic performance well beyond that of spherical powder materials.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Advances in Neodymium Ribbon Regenerator Materials


    Contributors:

    Published in:

    Publication date :

    2002-01-01


    Size :

    8 pages




    Type of media :

    Article/Chapter (Book)


    Type of material :

    Electronic Resource


    Language :

    English




    Advances in Neodymium Ribbon Regenerator Materials

    Felmley, T. | British Library Conference Proceedings | 1999


    A Neodymium Plate Regenerator for Low Temperature Gifford-McMahon Cycle Refrigerators

    Chafe, J. N. / Green, G. F. / Hendricks, J. B. | British Library Conference Proceedings | 1997


    Low Temperature Cryocooler Regenerator Materials

    Gschneidner, K. A. Jr. / Pecharsky, A. O. / Pecharsky, V. K. | Springer Verlag | 2003


    Low Temperature Cryocooler Regenerator Materials

    Gschneidner, K. A. / Pecharsky, A. O. / Pecharsky, V. K. | British Library Conference Proceedings | 2003


    Regenerator Materials Development and Testing

    Ross, R.G. | British Library Conference Proceedings | 2005