Techniques and technologies for far-infrared astronomy

Abstract

Far infrared astronomy is pivotal to our understanding of how the universe evolved, from the earliest galaxies to ongoing star and planet formation. Observations in the far infrared, however, are limited by thermal radiation in optics, and low spatial resolution. Reducing the noise brought about by thermal radiation of optical systems used in far infrared astronomy requires cryogenically cooled components. It is therefore important to understand how the physical properties of structural materials change in the cryogenic regime in order to understand their behaviour at operational temperatures. The design of a dedicated cryogenic materials testing site for probing thermal contraction and thermal conductivity of materials is presented. The characterization of two nanometer precision metrology systems is discussed, and the systems are used to measure the thermal contraction of aluminium and carbon fibre reinforced polymers to temperatures below 10 K. Suggestions for improvements in the experimental procedure are provided.