Muon Tomography Scanner Prototype

Tomographic scanner built at LNL, Padua

The CMT(p) project is a collaboration of the Universita’ degli Studi di Padova and the Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Padova.
The project is aimed to build a complete scanning system to test the usability and the effectiveness of the Muon Tomography. We want to use muon tomography to inspect non accessible volumes.
We are working on several, applications, from homeland security and environmental protection to quality control and human safety.
The most immediate application is to assess or exclude the presence of high density objects. This could allow the detection of hidden, shielded radioactive sources inside scrap metal headed to a melting facility.
Another application can be the identification of the presence of a nuclear device hidden in a van. We use it as a tool to identify a heavy material inside the scanning volume basing on its density.
But we plan to test its capability to check the distribution of radioactive waste inside the proper containers and to monitor the density distribution of melted metal inside a melting tank too. Our goal is to reach a high detection efficiency of the technique itself, while keeping a low rate of false positives with short inspection time. And short computational time too!

Scanning Prototype
We built a fully operative, muon-based scanning prototype at Istituto Nazionale di Fisica Nucleare (INFN) Legnaro National Laboratories (LNL) capable of acquiring data since 2009, and able to perform a fully passive tomographic scan since 2010.
The scanning system consists in a 3mx2.5mx1.6m inspectable volume (~12m3) enclosed in two 3m*2.5m muon tracking chambers. Those trackers are 2 spare devices from the muon tracking system of the CMS experiment in use at CERN laboratories in Geneve.
We study the tomographic technique using real data, both to stick to the problems that arise “on the track” and to test the reliability of all the MonteCarlo simulations we build for different applications of the muon tomography technique.

Prototype MonteCarlo Simulation

The MonteCarlo Simulation of the Prototype

MonteCarlo Simulation
We have real data that we can acquire in the prototype environment. To enlarge the horizon of possible application we built a MonteCarlo Simulation Environment. The LNL prototype has been accurately described. Therefore we throrouly tested the reliability of our SE against the real data to ensure the reliability of its results. Through the simulation, we can now explore the capability of the technique under different situations to test its capabilities for several applications.
Particles behavior and mechanical setup is simulated using the GEANT4 particle simulation tool, developed at CERN for particle physics experiments.

Shielded Radioactive Sources Detection
Under the Mu-Steel European Project, we used the simulated environment to move from the modest-scale scanning volume of the prototype to a full-scale portal.  Its size makes it capable to host an entire truck container. We tested the efficiency of the technique, and our software, in indentifying the presence of a shielded radioactive source hidden inside a container filled with scrap metal. The idea is to offer a device to scan trucks headed to melting facility that may hide an orphan source inside the shipped scrap metal. The results show that the system is able to offer a great contribution to protect the environment, and human health, from the menace of the accidental melting of a radioactive source.
The portal, truck, sources and scrap metal have been designed though a GDML implementation and the MonteCarlo data reconstructed in 3D images using our software.
We studied and built a prototype chamber for a next-generation scanning portal. This chamber is based on drift tubes detectors technology (unlike the CMS chambers used in the prototype), that allows to drastically reduce the cost of building a larger portal. Moreover, the drift tubes grant a better durability under harsh condition that may arise in an industrial environment.

Radioactive Waste Distribution
A new project has been submitted to the grant commission of INFN in behalf of our team. This project aims to the characterization of the distribution of the radioactive waste inside its containment cask. The possibility to check whether the condition of the spent fuel is critical without opening the drum can avoid or contain risks for human and environmental health. Due to the strict working condition, a new type of detector is planned to be used, based on gas ionization (GEM).

Efficiency tests and identification capability tests have been developed, implemented and applied both on the data coming from the prototype acquiring real muons and on the simulated data gathered by means of MonteCarlo simulations.
The results are on par with the present day prerequisites from industrial standards. We show the results of our work both in our pubblications and on the test cases page on this site.