David graduated from the University of Liverpool with a BSc degree in Physics, and was awarded a PhD from the same university, for research in nuclear structure. Following a fellowship, also at Liverpool, his career has been at NPL, starting in the Radioactivity Standards Group before moving to the Neutron Metrology Group.
Initial work in the Radioactivity Group was on decay scheme measurements, standardisation of electron capture nuclides, and ion chamber design. Since joining the Neutron Group,projects have involved: neutron fluence measurements at various energies; the measurement of proton and alpha particle energy deposition per ion pair (w-values) in gases of dosimetric interest; neutron spectrometry; and neutron dosimetry.
David is presently the Group Leader of the Neutron Metrology Group. He is chairman of Section III of the BIPM/CIPM Consultative Committee on Ionising Radiation (CCRI); is a member of IEC Technical Committee 85, as co-convenor of the working group on neutron reference radiations; and is on the editorial board of the journal Radiation Protection Dosimetry. He is the author of more than 80 scientific papers.
David Thomas's research interests are focused on the measurement of ionising radiation, in particular the characterisation of neutron radiation fields. Projects have included: the improvement of standard neutron fields, the development and utilisation of neutron spectrometry techniques, and the problems of neutron dosimetry for radiation protection.
Particular interests include: providing appropriate calibrations for neutron detecting devices, assessing the suitability of these devices for purpose, and the measurement of dose equivalent in workplace fields.