A test rig for analysis of adhesive tapes at 4 K cryogenic temperature

Cryostats and dewar vessels, in particular those used for liquid helium applications, are usually equipped with multi-layer insulation (MLI). Thereby, multiple foils are wrapped around the respective vessels, tubing and components. As standard, different foils are bonded edge to edge using adhesive tapes either based on aluminized non-metallic films or on aluminum foil. There are a number of standard test procedures for adhesive tapes near ambient temperatures (e.g. AFERA 5012/ISO 29863) allowing a standardized characterization of tapes in terms of holding force and long-term reliability. Unfortunately this does not hold true for adhesive tapes to be used at cryogenic temperatures. In this respect, a test rig comprised of a spring-based traction mechanism has been developed by the authors. Combined with a liquid helium dewar, the fabricated test set-up allows a precise and reproducible application of an adjustable tensile load at 4.2 K and measurements of the respective holding time. In the following, the overall set-up including its significant features is described and first experimental results with aluminum tapes are presented. (paper)