Thomas Athol Rafter (known as Athol) was born in Wellington on 5 March 1913, the son of Grace Ella May Clarkson and her husband, Michael Edward Rafter, a postal clerk. He was educated at Marist Brothers’ School, St Patrick’s College, Wellington, and Victoria University College, where he graduated BSc in 1935 and MSc in chemistry in 1938. During that time he was a Wellington athletic representative.
Unable to find a job as a research scientist, Rafter taught at St Patrick’s College, Wellington, and St Patrick’s College, Silverstream, from 1933 until a position became available at the Dominion Laboratory in 1940. He married Ruby Valarie Organ at Wellington on 2 December 1939; they were to have two sons and a daughter.
At the Dominion Laboratory, Rafter’s work initially concentrated on the analysis of coal ash. His reputation was boosted when he was asked to analyse uranium-bearing minerals from the West Coast beach sands. Some of these minerals were extremely resistant to fluxing agents but Rafter, in conjunction with Fred Seelye, a rock analyst, solved this problem by using an electric furnace to fuse the minerals with sodium peroxide in platinum dishes in order to increase their fluidity.
In August 1948, as a result of a cabinet decision to establish a group of scientists in the DSIR to undertake nuclear research, Rafter was sent to study at the Massachusetts Institute of Technology and Columbia University, New York, and to visit nuclear establishments in the US, Canada and England. After returning he began to develop the new technique of radiocarbon dating, which relies on detecting the residue of a radioactively unstable form (isotope) of carbon (carbon-14) in organic materials. He initially used it to measure the ages of volcanic ash showers. The original paper on radiocarbon dating, published by Willard Libby in 1949, gave very little detail and used a method based on counting solid carbon-14. However, the process was so tedious and difficult that Rafter, DSIR physicist Gordon Fergusson and their assistants decided to investigate gas-counting techniques. After several months of frustrating work they developed a technique using carbon dioxide gas, which provided radiocarbon age measurements to better than plus or minus 50 years – a major achievement for that time. He and his staff collaborated closely with New Zealand archaeologists in the dating of samples.
Throughout this period Rafter zealously encouraged New Zealand scientists to use radioisotopes, visiting Wellington, Palmerston North and Napier hospitals to discuss the use of phosphorus-32 in the treatment of blood cancers and iodine-131 for the diagnosis and treatment of thyroid cancers. His group provided a dispensing service for these isotopes from 1951 until 1956, when the hospitals set up their own nuclear medicine departments.
Following on from these successes, Rafter encouraged the DSIR and the university colleges to lobby the government for a build-up of nuclear science research in New Zealand. In 1958 he was made an OBE for services to science and education and in May 1959 he was appointed the inaugural director of the newly formed DSIR Institute of Nuclear Sciences at Gracefield, Lower Hutt, a position he held until his retirement in 1978.
Having established one of the world’s first radiocarbon dating facilities, Rafter was quick to realise the potential use of this new technique in geochemistry. He pushed through projects to study natural variations in the occurrence of radiocarbon and in the process discovered the link between atmospheric nuclear weapons testing and rising levels of radiocarbon in the atmosphere and the oceans. Rafter strongly supported the resulting project to monitor carbon dioxide in the atmosphere at Baring Head, near Wellington. He and his team contributed much to international understanding of the carbon cycle, and New Zealand’s present atmospheric chemistry research, in particular its expertise in trace gas isotopic techniques, stems from his foresight and encouragement.
Rafter also realised the potential of naturally occurring stable (non-radioactive) isotopes to increase our understanding of processes that occur in the environment. In 1953 he set up a sulphur isotope laboratory to study firstly coal, then geothermal sulphur, then he used the isotopic composition of co-existing sulphide minerals to determine ore deposition temperatures. He also developed techniques for the measurement of oxygen isotopes in sulphates, which were used in geothermal and environmental studies. In 1968 he was awarded a DSc by Victoria University of Wellington for this and his radiocarbon work.
Rafter served on a number of committees. He was a member of the board of the Wellington Cancer and Medical Research Institute (later the Malaghan Institute of Medical Research) from 1978 to 1990 (chairman 1982–85), the DSIR representative on the Radiological Advisory Council, and a member of the Council of Victoria University of Wellington. He served as a scientific representative on the Council of the Central Institute of Technology in the mid 1960s, and was chairman from 1969 until 1978. He held strong Catholic beliefs and gave a number of talks on science and religion to community organisations.
After his retirement, Rafter spent two years as the director of the United Nations Environment Programme Monitoring and Assessment Research Centre in London. In later years he spent much time on the bowling green, and took an interest in football and tennis. He frequently attended scientific lectures held at the Institute of Nuclear Sciences. To mark his 80th birthday in 1993, the institute’s radiocarbon laboratory was named the Rafter Radiocarbon Laboratory.
Athol Rafter was a deeply thoughtful man who saw no conflict between his science and his religious beliefs. He maintained an easy relationship with his staff and his energy and warmth allowed him to make lasting friendships with scientists throughout the world. He died in Wellington on 26 September 1996. Val Rafter had died in 1992, and he was survived by their children.