Thermal conductivity measurements of PTFE and AlO ceramic at sub-Kelvin temperatures
arXiv:1612.02514 · doi:10.1016/j.cryogenics.2017.05.008
Abstract
The design of low temperature bolometric detectors for rare event searches necessitates careful selection and characterization of structural materials based on their thermal properties. We measure the thermal conductivities of polytetrafluoroethylene (PTFE) and AlO ceramic (alumina) in the temperature ranges of 0.17-0.43 K and 0.1-1.3 K, respectively. For the former, we observe a quadratic temperature dependence across the entire measured range. For the latter, we see a cubic dependence on temperature above ~0.3 K, with a linear contribution below that temperature. This paper presents our measurement techniques, results, and theoretical discussions. Keywords: Thermal Conductivity, PTFE, AlO ceramic, Bolometer
11 pages, 11 figures, accepted by Cryogenics 27 May 2017, article reference JCRY2692