Professor Emeritus James Byrne
James (Jim) Byrne, a pioneering experimental physicist who developed innovative techniques to measure properties of the neutron, and who also helped to ensure the continuity and regeneration of the Experimental Particle Physics group at Sussex, passed away on 12 October 2022.
Jim joined the University of Sussex in 1965, and was therefore one of the original generation of physicists who, under the guidance of Roger Blin-Stoyle and Ken Smith, helped to establish the Department of Physics shortly after the University's founding. His main interests throughout the majority of his career were directed to making an accurate measurement of the free neutron lifetime, a highly significant parameter in understanding the cosmology of the Big Bang. Jim pioneered the Penning trap technique for this measurement, which - with ever-increasing precision - is still in use today, some 50 years later, in various laboratories around the world. He also carried out innovative measurements of the angular correlation of the electron and antineutrino that emerge from neutron decay, which can be used to test the validity and self-consistency of the Standard Model of particle physics.
Jim taught many students and supervised numerous PhDs throughout his career. His comprehensive 1994 textbook Neutrons, Nuclei and Matter: An exploration of the physics of slow neutrons has sold well around the world, and remains an essential reference for the field.
The late 1990s, when the first generation of physicists at Sussex were approaching retirement, was a difficult time financially for the University. Foreseeing changes in the research-funding landscape, Jim lay the foundations for the establishment of what is now a highly successful and thriving neutrino-physics group, thus passing on the baton to the next generation.
In addition to Jim's outstanding skills as a physicist, he was very well read and extremely good company. His experimental work was often carried out overseas, especially at the research facility in Grenoble, France, where he loved to spend time in the mountains and lakes. Jim was also an excellent tennis player and had a great love of rugby.
Jim is survived by his wife Astrid, their three children Andrew, Alice, and Kate - as well as two grandchildren.