The image above shows the interior of the liquid argon time projection chamber in one of the two protoDUNE neutrino detectors under construction at CERN, the European particle physics research centre on the French-Swiss border. This 10-metre-a-side refrigerated cube will hold an 800-tonne tank of the noble gas argon chilled to a liquid. When neutrinos collide with the argon atoms, they will produce tiny flashes of light that give away the paths.
The protoDUNE detectors are prototypes of the technology to be used in the Deep Underground Neutrino Experiment (DUNE), which is currently being built in a cavern 1.6 kilometres below ground in South Dakota, USA.
Researchers from 32 countries are working on the DUNE project, which may reveal more detail than ever before about the workings of the elusive neutrino.