LBNF/DUNE PIP-II Cryomodules

In September 2017, the UK announced a £65m collaborative investment as part of a long history of UK research collaboration with the US, which is the first major project of the wider UK-US Science and Technology agreement. UK Universities and Science Minister Jo Johnson signed the agreement with the US Energy Department to invest the sum in the Long-Baseline Neutrino Facility (LBNF) and the Deep Underground Neutrino Experiment (DUNE). DUNE will study the properties of neutrinos, which could help explain more about how the universe works and why matter exists at all. This investment is a significant step which will secure future access for UK scientists to the international DUNE experiment. Investing in the next generation of detectors, like DUNE, helps the UK to maintain its world-leading position in science research and continue to develop skills in new cutting-edge technologies. STFC will manage the UK's investment in the international facility, giving UK scientists and engineers the chance to take a leading role in the management and development of the DUNE far detector, the LBNF beam line and associated PIP-II accelerator technologies, thereby strengthening the UK's strategic partnership with FNAL in the USA. The UK's delivery of critical SRF accelerator systems for PIP-II will significantly enhance the world class skills already developed over many years in the field of SRF technology at Daresbury Laboratory, providing advanced preparation and testing infrastructure which can enable even larger scale and more complex technical system delivery for future national and international priority programmes. Such a UK delivery will also significantly escalate STFC's international leadership and prominence in this highly specialised field of expertise.

As part of the UK's In Kind Contribution (IKC) to the Deep Underground Neutrino Experiment, STFC will provide superconducting RF (SRF) cavities and assembled cryomodules for the new PIP-II SRF Linac at Fermilab, building on experience gained from the ESS high-beta cavity programme and the HL-LHC prototype cryomodule assembly which are both funded by the UK to conclude at Daresbury Laboratory in FY20/21. The scope of the expected delivery to FNAL will be to enhance UK industry fabrication capability for SRF accelerating structures, procurement of high purity niobium sheets and HB650 cavity fabrication to FNAL specifications and to validate the performance of these structures using the existing SRF testing infrastructure available at Daresbury Laboratory. Once testing has confirmed performance compliance, the cavities will be assembled and integrated into cryomodules using new assembly infrastructure to be provisioned, which will accommodate each 10m-long cryogenic vessel. Assembly of three HB650 cryomodules, each comprising six 650MHz high beta cavities will be prepared, which will then be shipped to FNAL for high power testing, prior to installation on the PIP-II accelerator.

The UK's leadership within the global DUNE/LBNF research project in the US will provide a broad array of impacts for a wide range of stakeholders, both during and post-project. These include:

[UK Research and Innovation (UKRI), and the UK academic base]
- Take a major stake and leadership role in the DUNE detector construction and secure access to the best physics for future UK exploitation;
- Significantly advance our understanding of the origin and structure of the universe, including study of the behaviour of neutrino particles and their antimatter counterparts, antineutrinos;
- Play a leading role in the LBNF beam line and associated PIP-II accelerator development at FNAL to exploit and build on the UK's world-leading expertise;
- Support research excellence through investment in the next generation of detectors - DUNE/LBNF is the new flagship global particle physics project;
- Nurture scientific talent: strong UK participation will provide unique and exciting training opportunities for PhD students in the UK, including application of cutting-edge deep learning and machine learning techniques.

[UK Government]
- Secure a strong economic return on the UK's capital investment;
- Enable the science base and industry to build core capability and capacity in key technologies;
- De-risk future capital expenditure in large-scale national research infrastructure through broadened UK fabrication base and enhanced expertise. Will give more freedom in future facility design choices, ensuring best use of UK research budget;
- Build a strong strategic UK-US partnership in science and innovation and help secure the UK's international reputation as partner of choice.

[UK industry]
- Accessible from publish access route. Accelerate product development. Procurement of advanced solutions. Driver for technological innovation. Benefit from lean production and industry best practise;
- Invest in knowledge exchange and innovation: key detector components will be manufactured in UK industry, leveraging the existing connections with industry from the ATLAS and experiments at CERN and SKA;
- Potential to access high value SRF manufacturing opportunities for the global research facility market, and to transfer technology to societal applications in healthcare, security and hand-held devices.

[General public}
- Stimulate public interest in fundamental physics, and help answer some of the big questions significantly advance our understanding of the origin and structure of the universe. This could provide insight as to why we live in a matter-dominated universe and inform the debate on why the universe survived the Big Bang;
- Develop cutting-edge skills in science and engineering and help inspire future uptake of STEM subjects in schools and universities;
- Increased global competiveness of UK industry, providing increased employment opportunities and apprenticeships;
- Transfer knowledge and technology advances to application areas in healthcare, security and semiconductor devices, for example, with significant societal impact potential in the longer term.

[STFC National Laboratories]
- Invest in the UK's scientific infrastructure - building manufacturing capacity and enhancing the existing skill base at the STFC Rutherford Appleton and Daresbury laboratories.

The mechanisms for optimising the economic and societal impacts generated by the PIP-II project are further detailed in the attached Pathways to Impact document.