A mobile high spatial-resolution muography instrument based on large-area Micromegas detectors

Muon radiography is an imaging technique based on muon absorption in matter that allows measurement of internal details in hidden objects or structures. This technique relies on measuring cosmic-ray muons tracks accurately, which reflects the incoming muon flux from both the target object and the open sky. In this paper, we report on the construction of a high spatial-resolution muography instrument based on Micromegas detectors. Using four layers of 400×400mm2 Micromegas detectors, channel multiplexing circuits, and the versatile readout system, a movable muography instrument named μSTC-R400 was designed and constructed. Results show that the channel multiplexing circuits can resolve hit positions correctly, and the spatial resolution of the detector is approximately 190μm. Experiments were conducted at an under-construction subway tunnel and outdoors near a mountain, demonstrating μSTC-R400’s ability to maintain high spatial resolution outside the laboratory and its robustness in harsh environments.