Secondary cosmic muons provide a powerful probe to explore various aspects of the world around us. Various physical processes have been employed over the last years for such applications. Muon absorption was used to probe the interior of natural and man-made structures, from the Egypt pyramids to big volcanoes, contributing to interdisciplinary studies. Multiple scattering was employed to reconstruct the location of scattering centres, producing 2D and 3D images of the interior of hidden volumes (muon tomography). Additional possibilities of cosmic muons have been exploited even for the alignment of large civil structures and in the study of their stability. All these applications benefit from the development of advanced detection techniques and improvement in software algorithms. This contribution surveys the state of the art of these applications, with special emphasis on their possibilities and limitations.
Part of the book: Cosmic Rays
In this chapter, a detailed description of the construction and the procedure for the measurement of performances of a charged particle imaging system is given. Such a system can be realized by the combined use of a position sensitive detector and a residual range detector. The position sensitive detector is made up of two superimposed and right-angled planes, each of which subsists of two layers of pre-aligned and juxtaposed scintillating fibers. The selected 500 μm square section fibers are optically coupled to two silicon photomultiplier arrays adopting a channel reduction system patented by the Istituto Nazionale di Fisica Nucleare. The residual range detector consists of 60 parallel layers of the same fibers used in the position detector, each of which is optically coupled to a channel of silicon photomultiplier array by means of two wavelength-shifting fibers. The sensitive area of both detectors is 90 × 90 mm2. The performance of the prototypes was tested in different facilities with protons and carbon ions at energy up to about 250 MeV and rate up to about 109 particles per second. The comparison between simulations and measurements confirms the validity of this system. Based on the results, a future development is a real-time radiography system exploiting high-intensity pencil beams and real-time treatment plan verification.
Part of the book: Applications of Optical Fibers for Sensing