Callisto | Cryogenic Test Services

The Dewar has been designed for the testing of RF and microwave components at cryogenic temperatures. However the Dewar is equally well adapted for testing other electronic circuits or even small mechanical components. The components to be tested are mounted on a cold plate within the Dewar enclosure, which is then evacuated before cooling with a two stage closed cycle Helium refrigerator. Base temperatures down to 12 Kelvin are achievable.

Test Dewar with top cover removed. Click the photo to see a detailed version of the Dewar.

Connection to the external world can be made to the device under test by means of a number of re-configurable access ports in the walls of the Dewar. Coaxial and/or waveguide test ports may be used depending on the application. Low thermal loss transmission lines are used inside the Dewar to ensure thermal isolation. Some additional multi-way electrical connections are also available for control, signalling or power circuits.

The Dewar is equipped with internal thermometers linked to an external computer for logging purposes. The computer and logger can also record analogue or digital parameters from the test bench in case that the recording of measured parameters as a function of temperature is required.

The maximum component size which can be accommodated is limited by the cold station enclosure size of 400mm x 400mm x 120mm.

Test Dewar Specifications
Base Operation Temperature	First Stage < 50 Kelvin Second Stage < 12 Kelvin unloaded
Test Enclosure Environment	Vacuum < 10 ^-6 Torr
Cold Plate Dimensions	400 mm x 400 mm
Internal clearance height above cold plate	120 mm
Cool Down Time from Room Temperature	~12 hours
Warm-up Time from base temperature	~20 hours without internal heaters ~ 8 hours with internal heaters
Cooling Power	First Stage 30 Watts Second Stage 6 Watts
Test Duration	Unlimited — close cycle refrigerator
Test Ports	4 x 50 mm ports configurable for coaxial or multi-way signal cables. 2 x 80 mm for waveguide or special-to-type interfaces. Additional multi-way cable up to 14 signal lines available.
Thermometry	Silicon Diode cryogenic thermometers on first and second stages.
External logging	Up to 20 analogue channels and 16 digital lines. Analogue parameters sampled at 60 readings/second (max). PC based data written to ASCII file.

Callisto offers a cryogenic tests service for clients wishing to evaluate the performance of components at low temperatures using the test Dewar described above. A comprehensive service is offered including:

Test planning, feasibility assessment, evaluation of test requirements and definition of needs for test jigs, interface adapters etc.
Provision of any necessary test jigs, adapters interface cables or transmission lines.
Installation of components to be tested.
Operation of cryogenic test Dewar and associated monitoring equipment.
Conducting or assisting in conducting measurements on components.
Test service report.

All testing will be done at Callisto's facilities located near Toulouse, France.

An RF Test bench is available for component testing which includes a scalar network analyser system operating up to 40 GHz.