T2K is a long-baseline neutrino oscillation experiment in Japan that searches for leptonic CP violation. The magnetised near detector (ND280) has the role of constraining the dominant systematic uncertainties, related to the neutrino flux and interaction cross section, in the measurement of the neutrino oscillation probability. To improve the sensitivity to the CP violating phase, ND280 underwent a major upgrade concluded this year. Key is the 2-ton neutrino active target, called Super Fine-Grained Detector (SuperFGD). It is made of approximately 2’000’000 optically-isolated plastic scintillator 1 cm3 cubes each one read out by three orthogonal wavelength shifting (WLS) fibers coupled to about 56’000 silicon photomultipliers. The three views make it capable of 4𝛑 particle tracking with a proton detection threshold down to about 300 MeV/c. Combined with the nanosecond single-channel time resolution, a unique feature of SuperFGD is the detection of neutrons produced by neutrino interactions with the measurement of the energy via time of flight. This year, the fully-equipped detector successfully took physics data detecting neutrinos produced at J-PARC. In this seminar, the design of SuperFGD, its construction and the performance in the neutrino beam will be presented.
Coffee will be served at 10:30.