Facility · Neutrinos
JUNO (Jiangmen Underground Neutrino Observatory)
Liquid-scintillator detector for reactor neutrinos (20 kt)
- Status
- Operating
- Location
- Jiangmen, Guangdong, China
- Operator
- JUNO Collaboration, IHEP (Chinese Academy of Sciences)
- Next
- Data taking; mass ordering at ≥3σ is several years away
Summary
The largest liquid-scintillator detector: 20 kt of scintillator about 53 km from two nuclear power plants. Its main goal is to determine the neutrino mass ordering and to measure oscillation parameters with sub-percent precision. Not to be confused with NASA's Juno spacecraft.
Now as of 4 Nov 2026
The first physics result was published in Nature in June 2026, on the cover: with 59 days of data, the uncertainty on two oscillation parameters shrank by about a third. This is not yet a determination of the mass ordering; it shows that the detector and the analysis work (China Daily). A global fit of existing data gives a slight (~2.2–2.3σ) preference for the normal ordering; that is not a JUNO result (arXiv:2606.14121).
Key dates
- Aug 2025Data taking beginsdone
- Jun 2026First physics result (Nature)done
- ≈ 2030Mass ordering at ≥3σ (estimates)expected