Thermal conductance of pressed contacts at liquid helium temperatures
Abstract
It is pointed out that the optimum design of cryogenic instruments requires accurate thermal models. The present models are limited by a lack of knowledge of the low temperature thermal conductance of the bolted joints which are typically used in the instrument-to-system interface. In connection with studies of pressed contacts, it has been found that the thermal conductance does not obey the Wiedemann-Franz law. The present investigation is concerned with the characterization of the thermal conductance of pressed contacts at liquid helium-4 temperatures, taking into account the dependence of thermal contact conductance on applied force and temperature. It is shown that for the 0.4 micron OFHC copper pressed contact pair, the thermal conductance varies roughly as the second power of the temperature, and increases with increasing applied force.
- Publication:
-
AIAA, 18th Thermophysics Conference
- Pub Date:
- June 1983
- Bibcode:
- 1983thph.confQ....S
- Keywords:
-
- Cryogenic Equipment;
- Liquid Helium;
- Thermal Conductivity;
- Bolted Joints;
- Copper;
- Infrared Instruments;
- Tables (Data);
- Fluid Mechanics and Heat Transfer