Design and Construction of a First Prototype Muon Tomography System with GEM Detectors for the Detection of Nuclear Contraband

TL;DR

This paper presents the design and construction of a compact muon tomography prototype using GEM detectors, aiming to improve detection of shielded nuclear contraband at borders and ports.

Contribution

It introduces a novel, compact GEM-based muon tomography system with high spatial resolution for enhanced detection capabilities.

Findings

Successful construction of a prototype with 10 GEM tracking stations

GEM detectors provide high spatial resolution enabling a compact design

Potential for improved sensitivity in detecting shielded nuclear materials

Abstract

Current radiation portal monitors at sea ports and international borders that employ standard radiation detection techniques are not very sensitive to nuclear contraband that is well shielded to absorb emanating radiation. Muon Tomography (MT) based on the measurement of multiple scattering of atmospheric cosmic ray muons traversing cargo or vehicles that contain high-Z material is a promising passive interrogation technique for solving this problem. We report on the design and construction of compact Micro-Pattern Gas Detectors for a small prototype MT station. This station will employ 10 tracking stations based on 30cm x 30cm low-mass triple-GEM detectors with 2D readout. Due to the excellent spatial resolution of GEMs it is sufficient to use a gap of only a few cm between tracking stations. Together with the compact size of the GEM detectors this allows the GEM MT station to be an order of magnitude more compact than MT stations using traditional drift tubes. We present details of the production and assembly of the GEM-based tracking stations in collaboration with CERN and the RD51 collaboration as well as the design of the initial front-end electronics and readout system.