Infrastructure

The performance of electronic devices can often be improved by lowering the operating temperature resulting in lower noise and larger speed. Also, new phenomena can be applied at low temperatures, as for instance superconductivity. In order to fully exploit low-temperature electronics, the cryogenic system (cooler plus interface) should be ‘invisible’ to the user. It should be small, low-cost, low-interference, and above all very reliable (long-life). The realization of cryogenic systems fulfilling these requirements is one of the topics of research in EMS. Testing of these systems take place in the instrumentation and cooling lab that is fully equipped for this purpose. The lab is located on the 1^st floor of the Carre building in room (CR1055). An impression of the lab is given below.

VACUUM EQUIPMENT

Cryogenic coolers are operated in a vacuum environment. Therefore, several vacuum chambers and dry turbo pumps are available in lab. We also have a very sensitive rest gas analysis (RGA) system.

Several dry turbo pumps and vacuum chambers.

Vacuum pump with RGA (0-200AMU).

TEMPERATURE, PRESSURE AND FLOW CONTROL AND SENSING

For the tests a lot of measurement equipment is available, such as cryogenic temperature controllers and sensors, pressure and mass-flow controllers and meters, and read-out electronics. Often, the data acquisition is done in Labview.

Cryogenic temperature, mass flow, and pressure sensing and control, and readout electronics.

Labview data acquisition.

CUSTOM MADE TEST FACILITIES

In most projects, experiments are done with custom made test facilities, especially designed for that project.

Left: cryogenic test set-up for the ESA 4.5 Kelvin sorption cooler experiment and right: a microcooler characterization set-up.

CRYOGENIC COOLER TEST PLATFORMS

In the lab, various commercial cryogenic coolers are available. For example, these coolers are used for measuring material properties at cryogenic temperature or as precooling stage. We have 1 mixed-refrigerant JT cooler system (Cryotiger), 3 Gifford Mc Mahon coolers, a Cryomech pulse-tube cooler and different Thales Stirling coolers in the lab.

From left to right: Cryotiger compressor, GM compressor, vacuum feedthrough, Thales heart scanner.

Left: pulse-tube cooler test set-up. Right: cold end of the pulse-tube cooler.

HYDROGEN GAS DETECTION AND HIGH PRESSURE EQUIPMENT

Very high pressures of up to 100 bar are used in several experiments. Also, self made Joule-Thomson coolers are operated with hydrogen. Therefore, the lab is equipped with a hydrogen gas detection system. High pressure reducers, Swagelok and VCR tubing and fittings are used in the set-ups.

Left: hydrogen gas detection below LEL. Right: Pressure reducers for high working pressures.

Compression fittings and VCR couplings for leak free and safe measurement set-ups.

Experiments on technical superconductors take place in the high current superconductivity lab. Here, superconducting cables and magnets are characterized. An impression of the equipment of the lab is given on this page.

Impression of the high current superconductivity lab. The cryostats are lowered in to a trench to gain more height for the inserts.

Cryostat for liquid helium with a press set-up for testing ITER cables. Part of a liquid Helium dewar is shown on the left.

A superconducting 15 Tesla magnet above its cryostat. The magnet has a cold bore of 80 mm.

Sample holder for critical current measurements of superconducting wires. The wire shown has a diameter of 0.8 mm, at 4.2 K and can carry currents up to 2000A. Our setup is qualified for ITER-wire quality control.