Cryogenics

Cryogenics is a classic enabling technology for cutting edge research. Most people don’t encounter it directly, but here at STFC, cryogenics is often a key component at the heart of our science programmes. As such, our Centre for Instrumentation has identified it as a key focus area defined by future facility requirements, and an area that will be underpinned by strategic investment.

What is Cryogenics?

UK ATC Goniometer
(Credit: STFC)

Cryogenics involves very low temperatures, towards ‘absolute zero’ - but it lies behind myriad of applications from food to healthcare, energy, science and space. Cryogenic cooling of devices and material is usually achieved using Liquid nitrogen, or liquid helium, however gases such as methane are used at our ISIS facility. Liquid nitrogen is a cheap, readily available way of lowering temperatures to -196˚C (or 77K on the Kelvin Scale which starts at Absolute Zero). Liquid helium is more expensive and more scarce, but is much colder at only 4K. Increasingly however, electromechanical ‘Cryocoolers’ are used to achieve equally low temperatures at the push of a button.

As well as mission-critical cooling systems for space and science projects (e.g. Large Hadron Collider, Planck Space Observatory), our capabilities directly benefit many sectors:

• Agri-tech: cold storage/transportation for the food industry
   
• Life science: cryoprobes for cancer treatment
   
• Power: prevention of overheating in underground cables and wind turbine technology
   
• Security and defence: remote sensing and Earth Observation
   
• Aerospace, electronics, telecommunications

Cutting-edge skills

Ben Green working on the last front end receiver for the Atacama Large Millimetre Array, (ALMA), for which STFC is supplying the cryostats.
(Credit: STFC)

• Home to the UK’s biggest team of low temperature technology experts, STFC’s track record includes development of:
   
  • The most successful closed-cycle cryocoolers ever flown in space
    
    Cryocoolers are required on many satellites to cool infrared and microwave detectors. We have been developing miniature closed cycle refrigerators for space applications for over thirty years. Our first ‘Closed Cycle Cryocoolers’, were developed jointly between our Technology Department and Oxford University, since then many of the coolers we have designed have been licenced to industry. Our expertise in this area is world-leading and has been used in the Planck spacecraft mission.
     
  • the ground-breaking ‘Rutherford Cable’ for use in high field magnets
    
    Our Rutherford Appleton Laboratory pioneered the development of a multifilament superconducting cable known as the ‘Rutherford Cable’. Invented for particle physics applications, this technology formed the basis for all superconducting accelerator magnet technology. Other developments in superconducting magnet technology at RAL led to magnets for Nuclear Magnetic Resonance applications, used extensively in the majority of MRI scanners world-wide and a host of other applications.
     
  • An extensive fleet of test cryostats supported by skilled technicians and full control and data logging capabilities
     
• Specialist expertise supports Diamond Light Source, the UK’s national synchrotron science facility, and the ISIS neutron facility
  
  Much of science involves low temperatures. We can see inside molecular structures more clearly if they’re in a lower energy state, as at higher temperatures the individual parts of the molecule move more freely. The sample environment in a high proportion of experiments at the ISIS neutron source and a growing proportion of those at Diamond consequently involve cryogenic temperatures. To enable world-class experiments, these large facilities also rely on superconducting systems, which only work at cryogenic temperatures.
   
• Designing, testing and building systems for ground and space-based astronomy

Cryogenics in Astronomy and Space Science

A KMOS Spectrograph being inspected by engineers in the lab at the UK Astronomy Technology Centre.
(Credit: STFC)

We get sharper images from outer space if the detectors are cold too, so astronomy experiments, such as the ALMA project, rely on cryogenically cooled detectors. The same applies to satellites like Planck, sent into space to pick up faint signals from shortly after the Big Bang. RAL Space were involved in the ALMA project, as well as that of the Planck Mission and the James Webb Space Telescope.

At the UK Astronomy Technology Centre we are providing novel design solutions through work in major projects including; a multi object spectrograph (KMOS) for the ESO (European Southern Observatory) very large telescope (VLT) and the MOONS (Multi-Object Optical and Near-infrared Spectrograph) international project to develop and build MOONS for ESO’s VLT in northern Chile.

Ground-based

We are heavily engaged in the Muon Ionisation Cooling Experiment (MICE) project where we are working with Oxford University to design and procure some of the superconducting magnets as well as the cryogenics for the hydrogen delivery system. We are also commissioning the pion decay solenoid for the same experiment.

We also have expertise in superconducting Helical Undulators and are working with ASTeC and the Diamond Light Source on planar undulators for synchrotron sources.

Next generation technology

• In response to a shortage and growing cost of helium, we have also developed the ISISStat®, as a collaboration between the ISIS facility and Oxford Instruments. The ISISStat® a top-loading cryogen free cryostat provides neutron scattering sample environment in the temperature range 1.25 – 300 K.
   
• The next generation of High energy Laser Amplifiers are cryo-cooled, leading to higher pulse energy, high repetition rates and higher efficiency, due to improved thermal conductivity and reduced thermo-optical effect. A new technology platform, called DiPOLE, is being developed which will enable pioneering and exciting new applications of laser technology. These developments will touch high value markets including security, energy, space, defence, manufacturing and health. They will also provide major benefits to science.

Cryogenics for Accelerators

• New generation of particle accelerators (for example - Free electron lasers or Linear Colliders) are based on Superconducting RF (SRF) technology that requires large helium refrigerators. At the heart of ALICE an electron accelerator at the Daresbury Laboratory are four SRF cavities operating at 2 Kelvin cooled by the largest cryogenic plant in the UK. In the last decade ASTeC at Daresbury Laboratory has developed world class facilities for the development of SRF technology and is one of key players in several international projects like HiLumi LHC.
   
• In collaboration with several universities in the UK, ASTeC has launched a new program of developing ‘Thin Film SRF’ technology to meet the needs of future generation of accelerators.
   
• In addition to these underpinning activities ASTeC is also working closely with the UK industries to enable them to bring the SRF technology to market.

Cryogenics Impact Study

STFC commissioned WECD to carry out a study on the impact of cryogenics. The report asserts that cryogenic-related economic activities could contribute between £1.6 billion and £3.3 billion to the UK economy in the next 10 years, with STFC, its university partners and industry all being key players in delivering this growth. Read the cryogenics impact study.