Cryogenics and Magnetics
16 Mar 2010




Cryogenics & Magnetics




​The Cryogenics Group at the Rutherford Appleton Laboratory has had a distinguished history. The group was responsible for the development of superconducting cable for use in high field magnets. Around the world this is now known as "Rutherford Cable". The group was responsible for the development of large high field magnets for particle physics experiments and the Delphi and H1 solenoids were built at the laboratory. At the time, these were the largest superconducting magnets in the world.

The superconducting solenoid has a length of 7.4 m and a diameter of 5.5 m with a cold mass of ~25 tonnes. The cryogenic system is designed to cool down and maintain the superconducting coil at 4.5 K during operation. The Division did all the necessary cryogenic, thermal and vacuum design for the major component and the integration of the solenoid with existing refrigeration plant at CERN.

More recently the group has built the End Cap Toroids for the ATLAS detector on the Large Hadron Collider at CERN. The group also designed the proximity cryogenics system for the ATLAS detector.

Latterly the group has been responsible for the development of closed cycle coolers for space applications. These have been licensed to industry in the UK and abroad. These are the most successful closed cycle refrigerators ever flown. These have been used on experiments such as the Along Track Scanning Radiometer (these were a series of remote sensing instruments), Improved Stratospheric and Mesospheric Sounder, Integral (gamma ray instrument) and others. The group is supplied the 4K cooler for Planck which will measure the cosmic microwave background with unprecedented accuracy.

The group is working on astronomy with the manufacture of 60+ 1m diameter cryostats for the Atacama Large Millimetre Array (ALMA). These contain ten detector channels and incorporate a novel method for rapid integration and repair.

The group is looking to the future, working on the development of helical undulators for the International Linear Collider, planar undulators for light sources and targets for a variety of nuclear physics experiments. The work on targets is a good example of the modelling work carried out for superconducting magnets being applied to other areas of research. The development of the next generation space coolers will be served by ongoing work into large long life compressors and low temperature regenerators. The group has a heavy involvement in the Muon Ionisation Cooling Experiment (MICE) which is a precursor to a neutrino factory. MICE uses three 22 litre liquid hydrogen absorbers. The group is developing the hydrogen delivery system and refurbishing the decay solenoid. The group has a long track record of working with industry and is keen to develop further links.