The application of muon tomography to the imaging of railway tunnels

TL;DR

This study demonstrates the use of portable muon tomography to effectively image railway tunnel overburden and detect hidden voids with high statistical confidence in a short scan time.

Contribution

First application of portable cosmic ray muon tracking for imaging entire railway tunnel overburden in the field.

Findings

Identified unknown overburden voids confirmed by authorities

Successfully detected hidden construction shafts as density anomalies

Achieved rapid imaging within approximately 30 minutes

Abstract

Cosmic Ray Muon Radiography utilizes highly-penetrating cosmic ray muons to image the density profile of an object of interest. Here we report on the first trial to use a portable field-deployable cosmic ray tracking system in order to image the whole overburden of a UK railway tunnel with short duration scans (c. 30 minutes). A unknown overburden void was identified and, post-trial, confirmed by railway authorities. These experiments demonstrate the identification of hidden construction shafts with high levels of statistical significance as density anomalies within the data.