We developed a soft and high thermal conductive heat link for cryogenic applications. The measured maximum thermal conductivity was approximately 18500 W/m/K at 10 K. This spring constant was 1/43 of that of a single thick wire with the same cross-sectional area at room temperature. We realized these performances by utilizing high purity aluminum (99.9999 %, 6N) and by stranding many thin wires that are 0.15 mm in diameter. The electrical Residual Resistivity Ratio (RRR) was also measured and used to estimate the thermal conductivity by Wiedemann-Franz law. We observed the size effect on the electrical conductivity, and evaluated the effect of mechanical deformation to the RRR. These evaluations allow us to design a pragmatic heat link for cryogenic application.
@article{arxiv.2003.13457,
title = {High Performance Heat Conductor with Small Spring Constant for Cryogenic Applications},
author = {Tomohiro Yamada and Takayuki Tomaru and Toshikazu Suzuki and Takafumi Ushiba and Nobuhiro Kimura and Suguru Takada and Yuki Inoue and Takaaki Kajita},
journal= {arXiv preprint arXiv:2003.13457},
year = {2021}
}