2 March 2020
A major review of the $888 million Proton Improvement Plan II (PIP-II) at Fermilab, America, has been conducted – with Daresbury Laboratory receiving strong acknowledgement for its in-kind contributions to the international project.
When complete, PIP-II will provide megawatt proton beams from an innovative linear accelerator, which will be used to generate intense neutrino beams which will be fired towards a vast detector array 800 miles away in South Dakota. PIP-II will power research at Fermilab for decades to come and the Deep Underground Neutrino Experiment (DUNE) will attempt to solve the origins of matter and ‘why we are here on this planet’.
The review involved more than 30 specialist assessors from the Department of Energy and various National Laboratories in the US. It checked, scrutinised and validated every element of the project delivery, and recognised STFC’s critical involvement.
BEIS recently announced £65 million investment for international projects hosted by Fermilab. Daresbury Laboratory will have responsibility for four programmes of work on the PIP-II project as part of this.
Superconducting radio frequency infrastructure
Providing all preparation, testing and assembly facilities which will be located in the superconducting radio frequency lab (which goes by the catchy title of SuRF Lab) and will include a new ultra-clean cleanroom facility, a large vessel assembly area and an extensive transformation of existing accelerator test facilities.
PIP-II will use superconducting radiofrequency (RF) cavities. RF cavities store the energy needed to accelerate a beam, in this case a proton beam, which when fired into a carbon or beryllium target will produce a high intensity beam of neutrinos. By making the cavities from niobium and super cooling them to 2 Kelvin they become superconducting – making them extremely efficient and needing very little power to perform the beam acceleration.
The project team will procure all materials and work with industry to have 18 high beta accelerating cavities built. They will then test the cavities - the chambers which drive protons to very high energies through the linear accelerator - to ensure they meet the operating specification determined by Fermilab.
UK industry development
The Daresbury team will work closely with The Welding Institute in Cambridge, who in turn will utilise specialist fabrication expertise from Shakespeare Engineering in Chelmsford and the Nuclear Advanced Manufacturing Research Centre in Sheffield. Collectively, they aim to master the UK’s first ever complete manufacture of superconducting accelerating cavities, made from very high purity niobium material.
Cryomodules are like very large insulating flasks. But rather than keeping things hot like your tea or coffee; they are used to keep the accelerating cavities extremely cold – to temperatures as low as -271°c (2 Kelvins).
Three cryomodules will be assembled and prepared on the Daresbury Laboratory site. Preparation of a cryomodule includes carefully connecting each of the six cavities together in the high classification cleanroom, assembling significant vacuum, cryogenic, instrumentation, alignment and control systems, each of which requiring their own testing and validation prior to final stage assembly. Once prepared, each cryomodule will be tested at Daresbury, then loaded onto a cargo aircraft transporter and shipped to Fermilab in Illinois. On arrival, they will be re-tested then will be ready for installation into the PIP-II accelerator tunnel.
To date, infrastructure development work has begun for the SuRF Lab and the cavity test facilities are currently qualifying prototype cavities. A plan for the proposed cryomodule assembly facilities has been submitted and design solutions are well underway to ensure the safe transportation of the completed cryomodules to Fermilab.
The PIP-II project will be undertaken on site for the next five years and almost 60 staff-years worth of effort from Daresbury Lab’s specialist teams will be critically involved.
Last updated: 02 March 2020