Abstract
Pure metals have extremely large thermal conductivity at cryogenic temperatures, and are therefore key materials for conduction cooling in cryogenic devices. Aluminum is a typical example of such a material, and as of recently, it can be highly purified and provided in commercial amounts. In this paper, the heat-transfer performance of 6N pure aluminum is reported, followed by a brief review of conduction theory on pure metals. It was confirmed that thermal conductivity of 6N pure aluminum fine wires reached 40, 000 W/(m K) at 6 K. This study also describes vibration transfer through a heat link made of pure aluminum, which is a critical issue for precise measurements, such as those using the cryogenic interferometric gravitational wave telescope. It is shown that use of stranded cable made of thin wires is effective for this purpose when the size effect of thermal conductivity does not dominate.
