Speaker
Description
The Short-Baseline Near Detector (SBND) serves as the near detector for Fermilab's Short-Baseline Neutrino (SBN) programme. It is a 112-ton Liquid Argon Time Projection Chamber (LArTPC) designed to search for new physics phenomena such as sterile neutrinos and study neutrino-argon interactions. Situated only 110 meters from the Booster Neutrino Beam (BNB), SBND has completed its first physics run, recording the world’s most extensive dataset of neutrino–argon interactions. SBND’s TPC subsystem hosts two drift volumes, each of which consists of three charge-sensing wire planes that detect ionisation electrons drifting from charged particles traversing the detector. A detailed understanding of electron transport within a LArTPC is crucial, as it directly influences how the recorded signal waveforms are translated into precise 3D reconstructions of neutrino interactions. One key transport property is diffusion, the gradual spreading of the ionisation cloud over drift time. Longitudinal diffusion, which occurs along the drift direction, directly affects the timing resolution and reconstruction precision. I will present studies of longitudinal diffusion in SBND at electric field strengths of 500, 400, 325, and 275 V/cm.