Properties of selected structural and flat flexible cabling materials for low temperature applications

TL;DR

This paper measures the low temperature thermal conductivity of various materials suitable for cryogenic supports and cabling, introduces a method for assessing heat transfer in flat cabling, and compares predicted and actual thermal conductivities.

Contribution

It provides new low temperature thermal conductivity data for multiple materials and a method to predict cable thermal properties from constituent layers.

Findings

Thermal conductivity data for materials at 0.5 to 5 K.

Validation of layered composition model for flex cable conductivity.

Method for measuring heat transfer coefficient of flat cabling.

Abstract

We present measurements of the low temperature thermal conductivity for materials useful in the construction of cryogenic supports for scientific instrumentation and in the fabrication of flat flexible cryogenic cabling. The materials we measure have relatively low thermal conductivity. We present a method for measuring the heat transfer coefficient of flat cabling and show, using an example, that the thermal conductivity of a flex cable is reasonably well predicted by composing the thermal conductivities of its constituent material layers. Room temperature physical and mechanical data is given for the materials studied, as well as an overview of relevant materials science and manufacturing details. Materials include Timet Ti 15-3 and Ti 21S, Materion alloy vit105 (LM105) in amorphous state, ATI Metals Nb-47Ti, Johnson Matthey nitinol (NiTi), Mersen graphite grade 2020, DuPont Pyralux coverlay and Vespel SCP-5050, and Fralock Cirlex polyimide sheets. All data is in the temperature range 0.5 to 2 K, and up to 5 K for SCP-5050.