Obituary of Cyril Delaney (1925-2012)

Cyril Francis George Delaney, Fellow Emeritus of Trinity College, University of Dublin, Ireland, and former professor of experimental physics, who died recently aged 87, was a outstandingly talented and inspirational scientist and a highly regarded lecturer to many generations of students.

After attending the High School, Dublin, Cyril entered Trinity College as an undergraduate in 1942. His achievements included an entrance exhibition, a foundation scholarship, and, in 1946, a double class I moderatorship (honours degree) in mathematics and physics together with a Large Gold Medal for his outstanding performance. Appointed in 1947 by the future Nobel Laureate, Prof ETS Walton, as a lecturer in physics, Cyril became in 1962 one of the few people in Trinity to have been promoted to Reader. In 1966 he was further promoted to the new professorship of experimental physics.

Cyril’s research centred on the physics of radioisotopes and radiation detectors, a rapidly developing field at the time. He also worked on the design and analysis of electronic circuits for detectors. Initially he spent several months in 1947 away from Dublin at the Institut du Radium in Paris. There he worked in radiation detection with the Nobel Laureates Irène Joliot-Curie (daughter of Marie Curie) and her husband Frédéric.

In his 1951 Trinity PhD thesis Cyril showed through a series of painstaking experiments how the naturally occurring and environmentally important radioisotope potassium-40 decayed. This work was published by the Royal Dublin Society. Over a period of 40 years he produced many articles and reports, together with two textbooks, one of which, Electronics for the Physicist, ran to a second edition.

Like his colleagues, his research students greatly valued his wise and knowledgeable guidance and advice. One of these students was Walton’s son, Philip, who went on to become professor of applied physics at the then University College Galway.

Cyril was experimentally highly skilful, often designing and building his apparatus and circuitry himself. Essentially he had no other option in the impoverished Ireland of the 1940s and 1950s, when almost no money was available to purchase equipment. He argued strongly that appropriate scientific funding would benefit not only researchers like himself but also the State as a whole. It took many years for such a national attitude to evolve, but meanwhile in 1961 he secured a gift, from the US, of nuclear instrumentation for teaching and research. In 1979 he obtained another such gift from the International Atomic Energy Agency.

Cyril travelled widely, even in the era before flying was common. He spent periods working at the Massachusetts Institute of Technology, US: the Atomic Energy Research Establishment at Harwell, UK; the Institute for Nuclear Studies near Wellington, New Zealand and the Institut Laue-Langevin, Grenoble, France. He gave valuable and conscientious service to committees in Euratom and elsewhere through Europe, as well as to the boards of Trinity College, the Dublin Institute of Advanced Studies and the then National Science Council and Nuclear Energy Board.

Cyril was a lively, enthusiastic and popular undergraduate lecturer. He also spearheaded public lectures on the issues surrounding the use of nuclear energy and of nuclear radiation in general. One of his early activities in Trinity was to emphasise the importance of radiation safety and dosimetry at a time when the use in Ireland of X-rays and nuclear radiation was not subject to any formal regulation.

Honours awarded to him included membership of the Royal Irish Academy and fellowships both of Trinity College and of the Institute of Physics.

Everyone appreciated his fairness and humour, and he enjoyed being a physicist. A man of profound Christian faith, he was modest, devoted to his family, and a superb handyman in the house. The selfless support of his family enabled him to continue living at home throughout his years of ill-health prior to his death. He is survived by his wife Mary, his children Susan, Ian, Janet, Catherine and Gwyneth, and by 14 grandchildren and one great grand-daughter.