Share

A compact thermal heat switch for cryogenic space applications operating near 100 K.

Author(s) : DIETRICH M., EULER A., THUMMES G.

Type of article: Article

Summary

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 (CTE) 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.

Details

  • Original title: A compact thermal heat switch for cryogenic space applications operating near 100 K.
  • Record ID : 30011430
  • Languages: English
  • Source: Cryogenics - vol. 59
  • Publication date: 2014/01
  • DOI: http://dx.doi.org/10.1016/j.cryogenics.2013.11.004

Links


See other articles in this issue (7)
See the source

Indexing