Development of a sorption-based Joule-Thomson cooler for the METIS instrument on E-ELT

Cryogenic Engineering Conference 2015

材料科学;物理学

Wu, Y.^1 ; Vermeer, C.H.^1 ; Holland, H.J.^1 ; Benthem, B.^2 ; Ter Brake, H.J.M.^1

University of Twente, P.O. Box 217, Enschede

7500AE, Netherlands^1

Airbus Defence and Space Netherlands B.V, P.O. Box 32070, Leiden

2303DB, Netherlands^2

关键词: Cryogenic cooling;    Extremely Large Telescopes;    Joule-Thomson coolers;    Sorption coolers;    Temperature level;    University of Twente;    Vibration-free;    Wavelength ranges;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/101/1/012170/pdf
DOI  :  10.1088/1757-899X/101/1/012170

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

METIS, the Mid-infrared E-ELT Imager and Spectrograph, is one of the proposed instruments for the European Extremely Large Telescope (E-ELT) that will cover the thermal/mid-infrared wavelength range from 3-14 m. Its detectors and optics require cryogenic cooling at four temperature levels, 8 K for the N-band detectors, 25 K for the N-band imager, 40 K for the L/M-band detectors and 70 K for the optics. To provide cooling below 70 K, a vibration-free cooling technology based on sorption coolers is developed at the University of Twente in collaboration with Airbus Defence and Space Netherlands B.V. (former Dutch Space B.V.). We propose a sorption-based cooler with three cascaded Joule-Thomson (JT) coolers of which the sorption compressors are all heat sunk at the 70 K platform. A helium-operated cooler is used to obtain the 8 K level with a cooling power of 0.4 W. Here, three pre-cooling stages are used at 40 K, 25 K and 15 K. The latter two levels are provided by a hydrogen-based cooler, whereas the 40 K level is realized by a neon-based sorption cooler. To validate the designs, three demonstrators were built and tested: 1. Full-scale 8 K helium JT cold stage; 2. Scaled helium sorption compressor; 3. Scaled 40 K neon sorption JT cooler. In this paper, we present the design of these demos. We discuss the experiment results obtained so far, the lessons that were learned from these demos and the future development towards a real METIS cooler.