Speaker
Description
The Jiangmen Underground Neutrino Observatory (JUNO) is a 20-kiloton multi-purpose liquid scintillator detector designed to determine the neutrino mass ordering and measure neutrino oscillation parameters with sub-percent precision. Following the completion of construction, JUNO began its first physics data taking phase in August 2025 and released world-leading precision measurements on the solar neutrino oscillation parameters with 59.1 days of data. The energy resolution in this initial data taking phase is 3.4% for $^{68}$Ge and 3.0% for $^{241}$Po at a similar energy. And efforts on a couple directions to further improve the energy resolution is ongoing.
This poster presents the characterization of the JUNO’s energy resolution evaluated with calibration sources ($^{137}$Cs, $^{54}$Mn, $^{40}$K, $^{68}$Ge and $^{241}$Am-$^{13}$C) and natural radioactivity. The energy resolution breakdown is studied with a full chain simulation using realistic detector response. Improvement strategies aimed at approaching the design goal are also discussed.