Obituary of Donald Perkins | Particle physics

Particle physicist Donald Perkins, who died at the age of 97, made fundamental discoveries about the structure of the proton and nuclear interactions at extreme energies, first proposing the use of beams of pion particles in the treatment of cancer. His career spanned the birth of particle physics, emerging from studies of cosmic rays in the 1940s, through its maturity in the last decades of the last century, right up to the discovery of its climax. Higgs boson in st. He played major roles all the time.

When Perkins began research in 1948, the electron, proton, and neutron were the only known fundamental particles whose roles in building atoms were understood. The major, a particle predicted to carry the strong force that binds atomic nuclei, was recently discovered in cosmic rays by Cecil Powell of the University of Bristol, and it was in Powell’s group that Perkins began his research career.

Powell pioneered the use of photographic emulsions to study cosmic rays. The technique involved going to high altitudes, such as the Pic du Midi, or using custom weather balloons, to get the best access to the rays. Perkins’ supervisor was J.B. Thompson, who had been active in the Second World War, and Perkins asked him to arrange a flight from RAF Benson in Oxfordshire to take his photographic emulsion at 30,000 feet and fly it for several hours.

Donald Perkins
In addition to research, Donald Perkins has delivered extensive lectures and his textbooks continue to educate and inspire new generations of particle physicists

Over the next few years, Perkins obtained many important photographs of pions in action. He was the first to notice the nuclear capture of the negatively charged pion and obtain evidence that the pion is unstable. With Powell and Peter Fowler, Perkins published an encyclopedia of emulsion images of cosmic ray interactions, Study of Elementary Particles by the Photographic Method (1959), which was state of the art in this field. In 1961, Perkins and Fowler first proposed the use of pion rays as a treatment for cancer.

Discoveries in cosmic rays inspired the birth of high-energy particle physics using ground-based accelerators, resulting in the discovery of a veritable zoo of particles. It was suspected that most of these elements were not fundamental, but it wasn’t until 1968 that there was direct evidence that the proton, and by implication others, consisted of even more fundamental particles. This breakthrough came from experiments in Stanford, California, where electrons were used to probe protons and neutrons. However, that the fundamental constituents were quarks, it was only established in 1972, thanks to Perkins’ insight.

An avalanche of particle discoveries was the discovery of the neutrino in 1956. This electrically neutral sibling of the electron fascinated. After becoming Professor of Elementary Particle Physics at Oxford University in 1965, where he built the modern Department of Nuclear Physics with Denise Wilkinson And the Ken AllenAt CERN in Geneva, Perkins began using beams of neutrinos as proton probes. There he was directly involved in two breakthrough discoveries that inspired the modern Standard Model of particles and forces.

Perkins was well acquainted with Stanford’s experiments with electrons and immediately, in 1968, persuaded a newly formed collaborative team to use Cern Gargamelle Bubble Room Bundles of neutrinos can provide a complementary view of the internal structure of a proton. This idea dominated the neutrino program at CERN, and by 1972 their data made it possible to measure the electrical charges of those components. Result: A proton and a neutron are composed of quarks bound together by gluons. By 1973, this had inspired the development of the modern quantum dynamics theory of highly interacting particles, a major underpinning of the Standard Model.

The strong nuclear force was understood, but the weak force, whose role is most commonly fueled by the Sun and causing forms of radioactivity, remained a mystery. The new theory, which unites the weak force with the electromagnetic force, has now received its first confirmation thanks to Perkins and the Gargamelle group. Neutrinos are unique probes of the weak force. They were known to pick up an electric charge when interacting with protons, but an emerging theory that unifies the electromagnetic and weak interactions required a previously unseen consequence of the weak force in which neutrinos bounce off unchanged protons.

Donald Perkins, right, and Norman Barford plunge a tube into the Aletsch Glacier on the Jungfraujoch River in the Bernese Alps in 1948, to test whether ice could be used to detect particles
Donald Perkins, right, and Norman Barford plunge a tube into the Aletsch Glacier on the Jungfraujoch River in the Bernese Alps in 1948, to test whether ice could be used to detect particles

The Gargamelle experiment played a leading role in proving the existence of these “neutral currents”, which paved the way for the final confirmation of the unified theory and the Nobel Prizes in 1979 for its theoretical creators, Sheldon Glashaw and Abdus Salam W. Stephen Weinberg. At the time of their consolidation agents, the massive W and Z bosons, were not discovered. The Gargamelle results, led by Perkins, were sufficient evidence by the Nobel Committee.

Perkins was a member of the Science Policy Committee at Cern from 1981 to 1986, and finally its Chairman, during which time he was the LEP, and Large electron-positron collider And an introduction to the stream Large Hadron Collider was being built. With the Standard Model anchored, the long march to find its fulcrum, Higgs boson, seem. Perkins’ graduate textbook, Introduction to High Energy Physics, first published in 1972, is now in its fourth edition and continues to educate and inspire new generations of particle physicists working at the Large Hadron Collider.

Donald was born in Hull, East Yorkshire, the son of Gertrude and George Perkins, teachers of English and mathematics, respectively. He was educated at the city’s Malet Lambert High School, and went on to Imperial College London, where he received a BA in Physics in 1945 and a PhD in 1948. He was a senior researcher in Royal Commission for the Exhibition of 1851 for three years, before becoming an Associate in Physics in 1951 at Bristol University. After a year at the Lawrence Radiation Laboratory, Berkeley in California, he returned to Bristol in 1956 as Lecturer in Physics, and was appointed Reader in 1960. He was at Oxford University, where he was a Fellow of St Catherine’s College, from 1965 until his retirement in 1993.

After being elected as a member of the Royal Society in 1966, he won the Society’s Royal Medal in 1997. He was awarded the Central Bank of Egypt Award in 1991.

Perkins married Dorothy Maloney in 1955. She died in 2021, and he is survived by their two daughters, Venetia and Michelle.

Donald Hale Perkins, particle physicist, born October 15, 1925; Died October 30, 2022

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