Design and performance of the FIT scintillating-fiber tracker

Tracking detectors based on scintillating fibers, read out with silicon photomultipliers (SiPMs), have emerged as a competitive alternative to silicon strip detectors in high-energy and astroparticle physics. The scintillating-fiber tracker (FIT), proposed for the upcoming High-Energy Cosmic-Radiation Detection (HERD) facility, consists of several tracking planes of fiber mats stacked along two orthogonal coordinates. FIT is designed to reconstruct the trajectory of traversing charged particles, measure their absolute charge, and enhance the photon conversion into electron-positron pairs. A prototype detector, named MiniFIT, has been produced and extensively tested in various beam-test campaigns at CERN. In this work, we will discuss the development of the FIT detector, as well as design and performance of MiniFIT.