A binned clustering algorithm to detect high-Z material using cosmic muons

Abstract

We present a novel approach to the detection of special nuclear material using cosmic rays. Muon Scattering Tomography (MST) is a method for using cosmic muons to scan cargo containers and vehicles for special nuclear material. Cosmic muons are abundant, highly penetrating, not harmful for organic tissue, cannot be screened against, and can easily be detected, which makes them highly suited to the use of cargo scanning. Muons undergo multiple Coulomb scattering when passing through material, and the amount of scattering is roughly proportional to the square of the atomic number Z of the material. By reconstructing incoming and outgoing tracks, we can obtain variables to identify high-Z material. In a real life application, this has to happen on a timescale of 1 min and thus with small numbers of muons. We have built a detector system using resistive plate chambers (RPCs): 12 layers of RPCs allow for the readout of 6 x and 6 y positions, by which we can reconstruct incoming and outgoing tracks. In this work we detail the performance of an algorithm by which we separate high-Z targets from low-Z background, both for real data from our prototype setup and for MC simulation of a cargo container-sized setup. (c) British Crown Owned Copyright 2013/AWE

Passive 3D imaging of nuclear waste containers with Muon Scattering Tomography

“…The method takes a similar approach as [13]. The imaging algorithm subdivides the volume under consideration into cubic bins.…”

Non-destructive assay of nuclear waste containers using muon scattering tomography in the Horizon2020 CHANCE project

“…Then, the volume under investigation is divided into voxels as described in ref. [4]. In each voxel with at least N reconstructed vertices, a metric discriminator m ij is calculated for each pair of tracks i and j of the N most scattered tracks,…”

High-resolution imaging of nuclear waste containers with Muon Scattering Tomography

“…In order to validate the simulation, data was taken with our prototype detector system [13] which used 50 × 50 cm 2 RPCs. The prototype system was built to provide experimental data for a study into the detection of lumps of high-Z materials in cargo containers [15,16]. These lumps are detected using the metric distance distribution of scattering vertices.…”