Development of Mudulus: A Muography Detector Based on Double-Synchronized Electronics for Geophysical Applications

Abstract

In this paper, we present a prototype modular muon detector ("Mudulus"), based on our previous experience with the design of the MuTe detector in Colombia and the AMIGA buried muon detectors in the Pierre Auger Collaboration. Our group is developing detectors for muography and multipurpose applications. Our prototype detectors use different modules of plastic scintillators with embedded optical fibers and 64 channel multianode photomultiplier tubes (PMTs) with a common dynode or arrays of Silicon Photomultipliers (SiPM). In the case of Mudulus, each module is made of 12 scintillator strips of (4 × 1 × 100) cm 3 coupled with a lengthwise running Wavelength Shifter (WLS) fiber, connected at each end to a PMT channel. This design allows us to build panels with up to four of these modules. This modular configuration allows changing the panel geometries looking for an adaptive shape or size to the studied object and resulting in a detailed muography image. The improvement in performance obtained with Mudulus is achieved by the combination of its modular design and the double-synchronized detection at the end of each scintillator bar. We take advantage of measuring at both ends of each strip to determine the muon flux using a model to account for signal attenuation in each anode, and then determine the position of the incoming muons with better discrimination and subpixel spatial resolution.