Timing characterization for T2K ND280Upgrade SuperFGD detector

Poster presented at the XXI International Workshop on Neutrino Telescopes - Padova 29 September - 3 October 2025 (https://agenda.infn.it/event/44606/) On behalf of the T2K Collaboration Abstract: The T2K experiment is a long baseline neutrino experiment, located in Japan. It studies neutrino oscillations by detecting accelerator neutrinos with a complex of near detectors and a far detector. ND280, one of the near detectors, provides a reduction of the neutrino flux and cross section uncertainties and performs cross section measurements.The new features of the upgraded ND280 detector allow to improve these capabilities. In particular, the newly installed target, the Super Fine-Grained Detector, which consists of small plastic scintillator cubes read out by three WLS fibers in the three orthogonal directions, offers high granularity and 3D reconstruction. This new detector design unlocks the sensitivity to neutron detection and reconstruction by measuring its time of flight in the detector.In such a context, the timing characterization of this detector is crucial. Here, a new methodology to perform time calibration for any high granular detector is described. By exploiting the granularity of the detector, it is possible to evaluate mis-synchronisation offsets and time walk contributions, along with the time resolution of the detector.The application and the results of this method are presented, allowing the upgraded ND280 to detect neutrons from real data.