Journal article

Publication year: 2014

Pages: 70-75

Journal: Cryogenics

Volume number: 59

ISSN: 0011-2275

eISSN: 1879-2235

Open access status: Green

DOI Link: https://doi.org/10.1016/j.cryogenics.2013.11.004

Publisher: Elsevier

Abstract: 
A thermal heat switch has been developed intended for cryogenic space applications operating around 100 K. The switch was designed to separate two pulse tube cold heads that cool a common focal plane array. Two cold heads are used for redundancy reasons, while the switch is used to reduce the thermal heat loss of the stand-by cold head, thus limiting the required input power, weight and dimensions of the cooler assembly. After initial evaluation of possible switching technologies, a construction based on the difference in the linear thermal expansion coefficients (CUE) of different materials was chosen. A simple design is proposed based on thermoplastics which have one of the highest CTE known permitting a relative large gap width in the open state. Furthermore, the switch requires no power neither during normal operation nor for switching. This enhances reliability and allows for a simple mechanical design. After a single switch was successfully built, a second double-switch configuration was designed and tested. The long term performance of the chosen thermoplastic (ultra-high molecular weight polyethylene) under cryogenic load is also analysed. (C) 2013 Elsevier Ltd. All rights reserved.

Harvard Citation style: Dietrich, M., Euler, A. and Thummes, G. (2014) A compact thermal heat switch for cryogenic space applications operating near 100 K, Cryogenics, 59, pp. 70-75. https://doi.org/10.1016/j.cryogenics.2013.11.004

APA Citation style: Dietrich, M., Euler, A., & Thummes, G. (2014). A compact thermal heat switch for cryogenic space applications operating near 100 K. Cryogenics. 59, 70-75. https://doi.org/10.1016/j.cryogenics.2013.11.004