[en] The Muon Portal Project has built a prototype of a real size detector ($6\text{m}\times 3\text{m}\times 7$ m) for the inspection of containers by muon tomography. This technique may provide 2D and 3D images of the interior of a container, to identify the presence of high-$Z$ materials. In the present Project, 4800 extruded scintillator strips were arranged such as to cover four X–Y detection planes ($6\text{m}\times 3$ m), two placed above and two below the container to be inspected. Silicon photomultipliers were used as photosensors, to collect the light transported by Wave Length Shifter (WLS) fibres embedded in the scintillator strips. First tomographic images are here presented.

[en] Traditional inspection methods are of limited use to detect the presence of fissile (U, Pu) samples inside containers. To overcome such limitations, prototypes of detection systems based on cosmic muon scattering from high-Z materials are being tested worldwide. This technique does not introduce additional radiation levels, and each event contributes to the tomographic image, since the scattering process is sensitive to the charge of the atomic nuclei being traversed. A new Project, started by the Muon Portal Collaboration, plans to build a large area muon detector able to reconstruct muon tracks with good spatial and angular resolution. Experimental tests of the individual detection modules are already in progress. The design and operational parameters of the muon portal under construction are here described, together with the preliminary simulation and test results. Due to the large acceptance of the detector for cosmic rays, coupled to the good angular reconstruction of the muon tracks, it is also planned to employ such detector for cosmic ray studies, complementing its detection capabilities with a set of trigger detectors located some distance apart, in order to measure multiple muon events associated to extensive air showers.

[en] The Muon Portal is a recent Project [1] which aims at the construction of a 18 m² tracking detector for cosmic muons. This apparatus has been designed as a real-size prototype to inspect containers using the muon tomography technique, i.e. by measuring the deflection of muons when traversing high-Z materials. The detection setup is based on eight position-sensitive X-Y planes, four placed below and four above the volume to be inspected, with good tracking capabilities for charged particles. The detection planes are segmented into strips of extruded plastic scintillators with WLS fibres to transport the light produced in the scintillator material to the photo-sensors (SiPMs) at one of the fibre ends. Detailed GEANT4 simulations have been carried out under different scenarios to investigate the response of the apparatus. The tomographic images are reconstructed by tracking algorithms and suitable imaging software tools. Simulations have demonstrated the possibility to reconstruct a 3D image of the volume to be inspected in a reasonable amount of time, compatible with the requirement of a fast inspection technique. The first two of the 48 detection modules are presently under construction. (authors)

[en] The Muon Portal is a recently born project that plans to build a large area muon detector for a noninvasive inspection of shipping containers in the ports, searching for the presence of potential fissile (U, Pu) threats. The technique employed by the project is the well-known muon tomography, based on cosmic muon scattering from high-Z materials. The design and operational parameters of the muon portal under construction will be described in this paper, together with preliminary simulation and test results

[en] The Muon Portal Project aims at the construction of a large volume detector to inspect the content of travelling containers for the identification of high-Z hidden materials (U, Pu or other fissile samples), exploiting the secondary cosmic-ray muon radiation. An image of these materials is achieved reconstructing the deviations of the muons from their original trajectories inside the detector volume, by means of two particle trackers, placed one below and one above the container. The scan is performed without adding any external radiation, in a few minutes and with a high spatial and angular resolution. The detector consists of 4800 scintillating strips with two wavelength shifting (WLS) fibers inside each strip, coupled to Silicon photomultipliers (SiPMs). A smart strategy for the read out system allows a considerable reduction of the number of the read-out channels. Actually, an intense measurement campaign is in progress to carefully characterize any single component of the detector. A prototype of one of the 48 detection modules (1 × 3 m²) is actually under construction. This paper presents the detector architecture and the preliminary results

[en] Cosmic ray tomography is a technique which exploits the multiple Coulomb scattering of highly penetrating cosmic ray-produced muons to perform non-destructive inspection of high-Z materials without the use of artificial radiation. A muon tomography detection system can be used as a portal monitor at border crossing points for detecting illegal targeted objects. The Muon Portal Project is a joint initiative between Italian research and industrial partners, aimed at the construction of a real size detector prototype (6×3×7 m"3) for the inspection of cargo containers by the muon scattering technique. The detector consists of four XY tracking planes, two placed above and two below the container to be inspected. After a research and development phase, which led to the choice and test of the individual components, the construction and installation of the detection modules is almost completed. In this paper the present status of the Project is reported, focusing on the design and construction phase, as well as on the preliminary results obtained with the first detection planes.