Detector developments for high performance Muography applications

Abstract Muography allows imaging of large scale objects using cosmic muons. As the observation point needs to be below the object of interest, either the detector is placed underground, and can reveal density structures, or, the detector can be on the surface and look sideways, capturing muons closer to the horizon. As the measurement time is fundamentally limited by the muon flux, long term operation must be achieved with high efficiency. Furthermore, reasonable imaging from a large distance requires good angular resolution. The relevance of addressing the out-of-laboratory environment is demonstrated on the example of a 4 square metre telescope targeting the Sakurajima volcano in Japan. For open air detectors, the suppression of the low energy (non penetrating) muon background can be reached with a telescope using absorber (scatterer) layers between detector layers with good position resolution. The presented Muography Observation System achieves that using MWPC-s, combined with the relevant servicing systems providing reliable power and gas supply, as well as data acquisition and transfer.