Performance evaluation of compact plastic scintillating fiber modules for muon tomography applications

Abstract: Muon tomography is a non-destructive imaging technique that exploits cosmic-ray muons from multiple directions. Its performance critically relies on stable, large-area, and high-resolution position-sensitive detectors. In this work, we report on the development of four compact scintillating fiber modules, each 100 cm long and composed of two staggered layers of 1 mm diameter fibers. The fibres are read out at one end by one-dimensional silicon photomultiplier arrays with a 2 mm pitch, coupled to Citiroc1A-based front-end electronics. The modules were characterised with cosmic-ray muons, yielding a detection efficiency above 97\% and a mean spatial resolution of about 0.56 mm, with uniform response over different distances from the readout end. These results demonstrate the suitability of this detector design for compact and large-area systems in muon tomography applications.