Donald Hill Perkins

Abstract Don Perkins was an outstanding experimental particle physicist who made his reputation studying cosmic rays with the photographic emulsion technique. He then used bubble chambers to make seminal contributions to the understanding of neutrinos. His major role in the discovery of weak neutral currents was the second time that he just missed a Nobel Prize. The first was his identification of what, with hindsight, was the first observation of the π meson. By analysing neutrino and anti-neutrino scattering data, and comparing them with earlier measurements of electron scattering, he provided compelling evidence for the reality of quarks as constituents of the proton and neutron. Perkins was a founder member of the Soudan collaboration, an experiment designed to detect proton decay. It found none, but placed an improved limit on the lifetime and made important studies of neutrino properties, laying the groundwork for the discovery of neutrino masses and mixing. Perkins’ theoretical work with collaborators Paul Harrison and Bill Scott on the mixing of the three flavours of neutrino remains relevant today. His first book was written in 1959 with collaborators Cecil Powell FRS and Peter Fowler (FRS 1964) on the emulsion technique; the second, his undergraduate text on particle physics, influenced generations of physicists.