British physicist Don Perkins, who played a significant role in shaping the world of particle physics from the 1940s onwards, passed away on 30 October at the age of 97.
After graduating from Imperial College, London, Perkins obtained a PhD under the supervision of Nobel Laureate George Paget Thomson. As part of his thesis work, he took a photographic emulsion onto an RAF transport plane to record cosmic rays at altitude. This resulted in what was later recognised to be the first observation of the pion, published in Nature in 1947.
In 1951, Perkins joined another Nobel Laureate, Cecil Powell, in Bristol, where, working with Peter Fowler, he discovered some of the decay properties of pions. This involved touring some of the world’s mountain tops with photographic emulsions, as well as sending them into the stratosphere on balloons. As a result of their studies, Perkins and Fowler were the first to suggest that irradiation with negatively charged pions might be used to treat cancer. In 1965, Perkins moved to Oxford where, under the overall leadership of Sir Denys Wilkinson, he established a world-leading particle physics group. One year later, he was elected a Fellow of the Royal Society, one of many honours that would crown his long career.
In the 1970s, Perkins’s research brought him to CERN, where his work with the Gargamelle bubble chamber contributed to the 1973 discovery of neutral currents, a seminal contribution to the field. He realised that combining neutrino and electron-scattering data established that both were scattering from quarks inside the nucleon. He was also an early supporter of quantum chromodynamics, the theory that describes the interactions between the quarks.
As the 1970s progressed, Perkins became increasingly interested in proton decay experiments, and was a leading advocate of the Soudan-II experiment in the United States. Although Soudan-II never saw evidence of proton decay, the experiment made important contributions to advancing the field of neutrino physics.
Over his long career, Perkins’s brilliance benefitted generations of physics students, many of whom were drawn to particle physics through his “Introduction to High Energy Physics”, a text book based on his undergraduate lectures first published in 1972. Besides his experimental and theoretical contributions to the field, Perkins was also active in the governance of particle physics, having chaired both the Nuclear Physics Board of the UK’s Science and Engineering Research Council and CERN’s Scientific Policy Committee. A charismatic and influential figure, his wisdom, delivered in a northern English accent and accompanied by his distinctive laugh, will be greatly missed by his many friends and colleagues.
Brian Foster