MSSL have comprehensive thermal vacuum and cryogenic vacuum facilites used for qualification and acceptance testing of flight hardware.
The MSSL vacuum cryostat is mainly used for testing/characterisation of flight CCDs. The cryostat consists of an outer stainless steel vacuum vessel with an inner stainless steel liquid nitrogen (LN2) vessel mounted within the outer vessel.
Thermal isolation between the inner and outer vessels is achieved by using Torlon 5030 thermal stand off spacers.This configuration ensures minimal external environment impact on the boil off rate of the liquid nitrogen and instrument under test. With CCDs and associated electronics mounted in the cryostat the liquid nitrogen vessel will allow for continuous instrument testing for twelve hours without the need to refill. Re-fill of the liquid nitrogen vessel can be performed at any time during testing which makes it possible to carry out lengthy test runs without the need to stop or re-configure the chamber.
Dimensions: 0.45m diameter by 0.8m (H).
Hardware mounting area: 0.4m diameter by 0.6m height
Base vacuum pressure: 5 x 10-5 mBar.
Temperature range: -150oC to +80oC
Temperature control: Closed loop PID control, +0.2o C -0.2o C.
Temperature measurement: 8 x 4 wire PT100 sensors.
Temperature and pressure logging: 8 channel plus pressure logging, user set logging interval.
Electrical feedthroughs: Various D-Sub connectors
Nominal, under vacuum