From a cubic kilometre of Antarctic ice to the deepest mines in the world — humanity's extraordinary instruments for catching ghost particles.
Nine major detectors spanning five continents, three oceans, and two polar ice sheets.
World's largest neutrino detector. 5,160 DOMs on 86 strings. Detected first PeV astrophysical neutrinos in 2013.
50,000-ton water Cherenkov detector. Confirmed atmospheric neutrino oscillations in 1998, Nobel Prize 2015.
Successor to SNO. Now filled with liquid scintillator for solar, reactor, and double beta decay physics.
Deep-sea neutrino telescope with two sites: ARCA (astrophysical) off Sicily, ORCA (oscillations) off France.
Fermilab's flagship experiment. 1,300 km baseline from Fermilab. Targets CP violation, mass ordering, proton decay.
Super-K's 5× larger successor. 260,000 tons ultra-pure water. Primary target: CP violation with T2HK beam.
First real-time spectroscopy of sub-MeV solar neutrinos. Detected pp, pep, CNO, and geoneutrino signals.
Gigaton Volume Detector in the world's deepest freshwater lake. Expanding to 1 km³ sensitivity.
Largest liquid scintillator detector. 53 km from reactors. Will determine mass ordering with sub-percent precision.
Four main detection strategies, each optimised for different neutrino energies and physics goals.
When a neutrino interacts with water or ice and produces a charged particle moving faster than light in that medium, a cone of blue light is emitted — analogous to a sonic boom for light. This Cherenkov ring is detected by arrays of photomultiplier tubes. The technique works at many energy scales, from MeV solar neutrinos to PeV astrophysical ones.
A neutrino interaction in an organic liquid causes a tiny flash of light (scintillation). This gives superior energy resolution and lower detection thresholds than Cherenkov, making it ideal for reactor, solar, and geo-neutrinos. The key challenge is extreme radiopurity.
Neutrino interactions in liquid argon produce ionisation electrons and scintillation light. The electrons drift in an electric field to fine wire grids, producing beautiful 3D images of particle tracks — like a digital bubble chamber with millimetre resolution. Best for detailed event reconstruction and νe appearance.
Pioneered by Ray Davis with 615 tons of perchloroethylene, solar neutrinos transform Cl into radioactive Ar atoms which are extracted and counted. The GALLEX/GNO and SAGE experiments used gallium. Slow but sensitive to the lowest-energy pp neutrinos. Davis won the Nobel Prize 2002 for this method.
Neutrino detectors must be shielded from cosmic rays — high-energy particles from space that create thousands of muons per second passing through any detector at the surface. Even a single misidentified muon can mimic a neutrino signal.
Rock, water, or ice overburden reduces the cosmic ray muon flux by many orders of magnitude. At SNOLAB (2,100 m underground), the muon rate is reduced by a factor of ~50 million compared to the surface — leaving only a handful per day to contend with.
The material surrounding the detector must also have ultra-low radioactivity — trace uranium, thorium, and potassium produce backgrounds that can mimic neutrino signals. This drives extraordinary purity requirements, down to parts per trillion.