Obituary of Prof. Cyril Delaney

15 October 2012

Cyril Delaney, Fellow of the Institute of Physics and former Professor of Experimental Physics at Trinity College Dublin, has died aged 87.

Prof. Cyril Delaney

He was an outstandingly talented scientist and a highly regarded lecturer to many generations of students.

Cyril Francis George Delaney was born in Dublin on 13th March, 1925, and died at his home in Co Kildare on 24th September, 2012.  His family was originally from Kilkenny, but he himself grew up in Dublin, where his father worked for the Esso petroleum company.

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 particularly outstanding performance.  

Appointed in 1947 by the future Nobel Laureate, Professor E.T.S. Walton, as a Trinity Lecturer in Physics, Cyril became in 1962 one of the few people there 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 Ph.D. thesis Cyril made a series of painstaking measurements on the beta particle emission from the naturally occurring and environmentally important radioisotope potassium-40.  

Three different schemes for its decay to argon-40 and calcium-40 had just been published, and he deduced that only one of the schemes, the one now currently accepted, could fit all the available experimental data. 

In the same year he presented his work at the Royal Dublin Society and published it in the society’s scientific proceedings.

Over a period of 40 years Cyril published many other scientific articles and reports, together with two textbooks.  

One was on radiation detectors, while the other, ‘Electronics for the Physicist’, ran to a second edition.  

Like his colleagues, his many research students greatly valued his wise and knowledgeable guidance and advice.  

One of his 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 much of his apparatus and circuitry himself.  

Essentially he had no other option in the impoverished Ireland of the 1950s, when almost no money was available to purchase scientific 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 managed to secure a significant gift from the U.S.A. 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, U.S.A., the Atomic Energy Research Establishment at Harwell, U.K., 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.  

In Ireland he served on 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.  

Shortly before his retirement in 1985 he also spearheaded a series of lectures for the general public on the issues surrounding the use of nuclear radiation.  

In fact 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 Fellowship not only of the Institute of Physics but also of Trinity College Dublin.

Cyril’s sense of humour was appreciated by all. He was a modest man, 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 many years of ill-health prior to his death.  

A man of profound Christian faith, he attended meetings for worship each Sunday in his own and other people’s houses. His funeral, conducted in his house, was attended by very many people, as was his burial afterwards. He is survived by his wife Mary, his children Susan, Ian, Janet, Catherine and Gwyneth, and by 14 grandchildren and one great grand-daughter.