Design and Performance of MiniFIT, the small-scale version of the HERD particle tracker

The High Energy cosmic-Radiation Detection facility (HERD) will be the largest calorimetric experiment dedicated to the direct detection of cosmic rays. HERD aims at probing potential dark-matter signatures by detecting electrons from 10 GeV, and photons from 500 MeV, up to 100 TeV. It will also measure the flux of cosmic protons and heavier nuclei up to a few PeV per nucleon, shedding light on the origin and propagation mechanisms of high-energy cosmic rays. HERD will be equipped with a scintillating-fiber tracker (FIT) read out with silicon photomultipliers. It will enable the reconstruction of charged particle trajectories, the measurement of their absolute electric charge, the enhancement of the conversion of photons into electron-positron pairs. A miniature version of the FIT sector, called MiniFIT, was designed, built and tested with particle beams at CERN. This contribution will delve into the design and physics performance of MiniFIT, particularly focusing on its position resolution and charge measurement capability.