Speaker
Description
The JSNS²-II (the second phase of the J-PARC Sterile Neutrino Search at the J-PARC Spallation Neutron Source) experiment aims to search for sterile neutrinos using two detectors located at baselines of 24 m and 48 m. To directly test the LSND anomaly, JSNS²-II employs the same neutrino source, the same neutrino target, and the same interaction channel as the LSND experiment. At the J-PARC Material and Life Science Experimental Facility (MLF), a 3 GeV proton beam is injected on a mercury target, producing muon antineutrinos via muon decay at rest. The JSNS²-II far detector contains approximately 32 tons of gadolinium-loaded liquid scintillator in the acrylic target region and about 131 tons of gadolinium-unloaded liquid scintillator in the gamma catcher region and veto region.
The far detector has been completed and is currently commissioning and performing calibration. Several commissioning activities are in progress, including nitrogen purging of the Gd-loaded liquid scintillator to remove oxygen, installation of a level stabilizer system to maintain a stable liquid scintillator height, and the development of a specific trigger to efficiently identify the physics events.
In this presentation, we report the latest status of the JSNS²-II far detector, focusing on commissioning progresses mentioned above.