Lee Thompson is a professor of physics at the University of Sheffield where he is also head of the high energy particle physics group. Lee has more than 35 years experience as an experimental particle physicist working at CERN, Fermilab (in the US) and, more recently, on the Japanese long-baseline neutrino physics programme. Lee’s interests in muon tomography largely focus on applications including the imaging of civil infrastructure and nuclear waste as well as the safeguarding of nuclear waste geological disposal facilities. In 2019 Lee co-founded a University spin-out company called Geoptic which is applying muon tomography techniques to the UK rail network where the method is being used to identify and characterise the presence of hidden voids in railway tunnels.