Cryogenic equipment

Thermal environments inside the vacuum chambers can be simulated by means of dedicated shrouds, fed with nitrogen and/or helium.

NITROGEN thermal system

The temperature excursions are obtained with dedicated home made TCUs (Thermal Conditioning Units). Simulated hot and cold cases are achieved with temperature controlled gaseous nitrogen (GN2) feeding thermal panels inside the vacuum chamber. A temperature range from 123 °K to 353 °K can be obtained on the thermal shrouds. Each panel can be individually driven to a specific temperature profile. For colder applications, the thermal system is switched to liquid mode (LN2) and uniform temperature around 85 °K are measured.

It is possible to reach higher temperature than 353 °K with additional heaters glued on the specimen or with Infrared lamps installed inside the thermal tent.

The thermal regulation system is designed to avoid oscillations and drift problems.
It warrants performances about +/-0.1 °K in long term stability and allows complex thermal cycling tests.

HELIUM thermal system

The Helium thermal system is composed of closed loop lines fed by one of both Helium liquefier/refrigerator (KOCH, model 1630 with a 45 [l/h] capacity or LINDE TCF 20 with a 50 [l/h] capacity) available at CSL. These lines can be fed with gaseous or liquid Helium.

For the cold gaseous Helium lines, the temperature can be controlled from 300 °K to 4.6 °K. The total power is 72 W at 5 °K or 200 W at 15 °K or 300 W at 18 °K.

Liquid helium lines are also available thanks to dewars fed by the liquefiers.

It should be noted that the system architecture allows to feed the lines with warm Helium up to 353 °K.

The two liquefiers are located in the same clean room but a distribution box allows to feed all the vacuum chambers (excepted Focal 1.5).