Speaker
Description
The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose experiment featuring a 20,000-ton liquid scintillator central detector, water cerenkov detector and top track, primarily designed to determine neutrino mass ordering. Following detector construction completion in late 2024, the detector was successively filled with ultrapure water and then liquid scintillator (LS). As LS filling started, the detector simulation required comprehensive tuning to adapt to the final mechanical geometry and updated operational conditions.
We have conducted systematic Monte Carlo tuning within the JUNO detector simulation software framework based on Geant4.This involved updating geometry models with detailed components like photomultiplier tubes (PMTs) and optimizing key optical parameters for the PMTs, LS and water. The tuning was rigorously constrained by data from the commissioning and physics data taking phases, including laser calibration and radioactive source (⁶⁸Ge, AmC) measurements.
The tuned simulation shows significantly improved agreement with experimental data in critical observables such as light yield, PMT hit counts, and hit-time distributions. This high-precision simulation version now serves as the benchmark for all ongoing physics analyses within JUNO, forming a solid foundation for achieving its core physics goals.