Links
NASA Goddard Cryogenics Group

DESIGN AND TEST OF POTENTIAL CRYOCOOLER COLD FINGER INTERFACES

L. M. Sparr, R. Boyle, L. Nguyen, H. Frisch, S. Banks, E. James, V. Arillo Code 713, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 USA

NASA/GSFC has undertaken testing to develop advanced techniques for thermal interfaces between a cryocooler coldfinger and its load to be cooled. The fundamental goal is to develop a six degree of freedom, flexible thermal strap which would mitigate the propagation of any residual vibration from the cryocooler to the load while keeping any increase in thermal resistance and weight to a minimum. A cryogenic test dewar, designed for use at liquid nitrogen temperatures (77K), was fabricated to permit accurate vibration and temperature measurement. A six degree of freedom metallic thermal strap was designed and fabricated, and its performance was evaluated as a baseline. A number of advanced concept thermal straps were also fabricated and evaluated. This paper describes the testing to measure vibration damping and thermal performance characteristics of the straps at cryogenic temperatures and compares the performance of these advanced thermal strap designs with the performance of conventional copper braided thermal straps.

Advances in Cryogenic Engineering Vol. 39 p. 1253 (1994).