Physicists at the University of Liverpool have reached a major production milestone on a global mission to understand why the Universe contains far more matter than antimatter. Half of the 137 giant neutrino sensors being built by the UK team for the Deep Underground Neutrino Experiment (DUNE) are now complete.
The sensors, known as Anode Plane Assemblies (APAs), are being manufactured by a team of 25 technicians and engineers at the Science and Technology Facilities Council's (STFC) Daresbury Laboratory, located at Sci-Tech Daresbury in the Liverpool City Region. The University of Liverpool is working in close partnership with teams at Lancaster, Manchester, Sheffield, Sussex and Imperial College London on the project.
What the sensors do
The APAs will detect tiny electrical signals produced when neutrinos interact with liquid argon inside DUNE's underground detector. Each APA is approximately 6.3 metres tall and 2.3 metres wide — roughly the height of a two-storey building. Each carries approximately 24 kilometres of hair-thin copper-beryllium wire, held in place by thousands of precision connections.
The UK is responsible for producing 137 of the 150 APAs required for the experiment. Eight completed APAs have already arrived at Fermilab in Illinois for final testing, ahead of installation at the underground detector in South Dakota.
The global experiment
DUNE will send a beam of neutrinos 1,300 kilometres across the US, from Fermilab in Illinois to the Sanford Underground Research Facility in South Dakota. The experiment aims to investigate why matter dominates over antimatter in the Universe, how neutrinos behave and change as they travel, and what can be learned from neutrinos produced by supernovae.
Neutrinos are among the most abundant particles in the Universe but rarely interact with matter, making them extremely difficult to detect. The underground facility will shield the detector from cosmic rays and background radiation that could interfere with the faint signals DUNE is designed to detect.
University of Liverpool physicists, led by Professor Christos Touramanis, are part of the DUNE international science project. The UK-wide collaboration brings together 14 universities and two national laboratories, with UK scientists and engineers contributing detector systems, software, computing and accelerator infrastructure.
Timeline
The remaining APAs are due to be completed in April or May 2029 and delivered for installation in South Dakota between January and November 2029.