Cryogenic application

The challenge for CSL is to reproduce on ground space conditions and deep cold space all around the instrument or satellite, if required by the mission.

Dedicated hardware are designed and built to answer to these requirements

Thermal tent

• Dedicated thermal tents are designed to surround the specimen and to reproduce the thermal conditions as in flight

• To design dedicated thermal tents, Esatan/Esarad is used to model the global set-up with the specimen. The goal is to define the best configuration, to estimate the set-up influence, to analyze the heat fluxes, to realize a sensitivity analysis for critical parameters.

 

• A dedicated thermal tent composed of copper panels mounted on a structure is generally designed for each specimen to test. This thermal tent can be fed with regulated nitrogen or cold helium gaseous. The thermal tent can be also designed with a double wall (GHe+LN2) to minimize heat leaks.

 

• To increase the absorptivity (α) on the thermal panels, CSL has developed the process to install open honeycomb with adapted black painting on the copper panels.

Specific designs

Helium bath

For a specific requirement to have a RF cold black body in front of the instrument, CSL designed a dedicated hardware to place in the middle of the spacecraft.

The system was designed to be :

• < 5K
• stability : 1 [mK] over 1 [min] reached
• homogeneity : 0.1 [K]
• autonomy : 3 days

 

Charcoal panel

 

 

 

 

 

 

 

For a specific requirement to minimize the helium partial pressure in the vacuum chamber, CSL designed a cold charcoal panel.

This was designed to trap the helium molecules. This charcoal was a LHe bath type shroud with a tank to increase the autonomy. Charcoal pellets were glued on fanned tubes.

Thermal control at interface

 

 

 

 

 

 

Specific thermal designs are used to control the interfaces between specimen and support which is a large heat input.

Copper strapping can also be designed to increase an item slope by conduction.