Development and Testing of a Modular Large-Area Cosmic Ray Telescope Using Scintillator-Fiber Hybrid Design for Millimeter-Level Muon Tracking

Abstract

Cosmic-ray muons, owing to their high penetration power and abundance, have been widely employed as a natural probe in experimental particle physics. We developed a meter-scale cosmic-ray muon telescope, consisting of two parallel super-layers (1 m $\times$ 1 m) separated vertically by one meter. A super-layer is composed of two orthogonal detection layers, of which each consists of eighteen modules arranged in parallel and packed closely together. A module consists of a plastic scintillating bar precisely aligned and stacked on top of an underlying scintillating fiber mat in which fibers are arranged in a row of bundles. For a detection layer, each scintillator bar is coupled to a PMT while fiber bundles at the same position within all modules are coupled to a single PMT. Signals from scintillating bars and fibers are combined together to determine hit positions. With this detection scheme, the telescope can meet the requirement of spatial resolution and reduce the number of readout electronic channels. This article presents the comprehensive development of the telescope, encompassing its geometric design, data acquisition system, and performance evaluation. Experimental results show that the telescope achieves a position resolution better than 2 mm and an overall detection efficiency of $\sim$85%. The innovative design keeps the manufacturing cost low while maintaining high spatial resolution and detection efficiency.