One would have hoped that the father of nuclear science, Lord Rutherford, would have conducted some experiments in nuclear science in his early work while a student at Canterbury College, Christchurch. New Zealand cannot claim such distinction. Ernest Rutherford's first paper published in the Transactions of the New Zealand Institute in 1894 was on the magnetisation of iron by high-frequency discharges. His second paper, published also in New Zealand in 1895, was on magnetic viscosity. Even his third paper which he produced when he was studying at Trinity College, Cambridge, as an 1851 Exhibition Scholar, was on magnetic detection of electrical waves. His fourth paper, published in the Philosophical Magazine in 1896, studied the ionisation of gases, first by roentgen rays and then by ultra-violet light. This led him eventually to the rays from the radioactive element uranium and the electrical conduction produced by such rays. It was just five years after his first experiments in New Zealand under Professor A. W. Bickerton and at Cambridge under Sir J. J. Thompson that he established himself along the path that made him one of the greatest figures in the history of science.
Lord Rutherford visited New Zealand in 1914 and at the Wellington Town Hall gave what must be the most historic lecture ever delivered to a New Zealand audience when he explained and demonstrated his nuclear theory of atoms by a magnetic model which illustrated repulsion between the oncoming alpha particle and the newly discovered nucleus of matter. In 1924 he returned for the last time to his native country. While Rutherford never worked in New Zealand, there came from his laboratories to our shores men whose scientific calibre was reflected in the positions each attained. Such scientists were Professor D. C. H. Florance, professor of physics at Victoria University College, who worked as a student under Rutherford at Manchester, as did Sir Ernest Marsden, past secretary of the D.S.I.R., who did the original famous experiment which led Rutherford to the discovery of the nucleus of matter. Dr D. H. Black worked under Rutherford at Cambridge but never returned to New Zealand. Dr L. Bastings, who recently retired from the Dominion Physical Laboratory, is still actively engaged in promoting the importance of physics in building research. To these men Rutherford was not only a great teacher and scientist but also a valued counsellor and friend. His spirit – the pursuit of scientific truth – they brought with them to New Zealand, his advice and friendship they passed on to a younger generation of New Zealand scientists. With the stimulus of such an outstanding New Zealand scientist overseas, it was not long before the applications of the scientific principles he pioneered found their way to New Zealand.
In 1906 J. H. Howell examined a number of New Zealand mineral springs and deposits in an attempt to explain their therapeutic properties in terms of the known germicidal properties of radioactive substances. This paper was followed in 1909 by an examination of the radium content of igneous rocks from the subantarctic islands of New Zealand by C. C. Farr and D. C. H. Florance of Canterbury College, and their findings were communicated by Rutherford to the Philosophical Magazine of London. Rutherford sent a solution containing 3·14 10-9 gram of radium to Farr to be used in the standardisation of his electroscope. Interesting rocks tested were an andesite from Ngauruhoe, lava from the crater of Mount Erebus, and a meteorite that fell at Mokoia in 1908. These specimens were shown to contain amounts of radium of the order 0·3 to 26 10-12 g radium per gram of rock.
What must be considered as one of the first studies of the applications of radioactivity was also made by Farr and Florance in 1909. They examined Christchurch artesian waters for radium emanation and stated that “as this gas has properties of a remarkable and energetic character, it occurred to us to endeavour to ascertain whether any, and if so, what, effects on animal life could possibly be ascribed to it”. They appeared to find some correlation between radioactivity of the waters and a disease called blue swelling amongst young trout in the yolk-sac stage. In a later paper, 1910, C. C. Farr and D. B. MacLeod stated that it was practically impossible to decide between a defect of oxygen and an excess of radium emanation as the cause of the increased mortality both in the egg and in the yolk-sac stage of the trout.
Using the same standard radium solution prepared by Rutherford, J. S. Maclaurin, Dominion Analyst from 1900 to 1930, discussed in the forty-fifth annual report of the Dominion Laboratory, 1911, work by himself and C. M. Wright on the radioactivity of the thermal waters of Rotorua, Taupo, and Te Aroha. Radium emanation given off from radium was boiled out of water, dried, and passed into an electroscope. These waters contained very much less than 10-1 2 g per c.c. while the radium content of sinters in the thermal areas were reported as containing nearly 10-1 2 g radium to a gram of sinter.
Ten years later, in 1921, work on the radioactivity of thermal waters was extended by F. J. T. Grigg, Dominion Analyst (1947–60), and M. N. Rodgers, then doing an M.Sc. thesis at Victoria University of Wellington. This work was stimulated likewise by the possible beneficial effects of ionising radiation to health. In 1922 Grigg and W. J. Phillipps, of the Dominion Museum, were able to show that it was not radium emanation but lack of dissolved oxygen that caused mortality in trout young. Farr of Canterbury College still kept up his interest in radioactivity for in 1927 he suggested to M. N. Rodgers a possible correlation between radioactivity and goitre incidence. The high radium emanation of Christchurch artesian waters made such a study possible, but no correlation of radioactivity with goitre incidence could be found. A correlation of goitre with lack of iodine in water was shown also in this paper.
R. R. D. Milligan, of Christchurch, who had been participating in the experiments of Farr, Florance, and Rodgers, decided to test whether there was any causation of goitre production through radium emanation. He injected six rabbits with large doses of radium emanation (radon). The rabbits thrived, showed no abnormal symptoms, and it did not appear that radon could be an important factor in the appearance of goitre, at least among rabbits.
It was another 15 years before New Zealand scientists concerned themselves in the applications of nuclear science, so ably championed by Rutherford up to his death in 1937. This may have been due to the detection of nuclear phenomena passing from the simple electroscope to more expensive nuclear machines that were available only in a few advanced research laboratories overseas.
The Second World War and the chaos it wrought through the use of nuclear weapons changed the emphasis of science in a world of rapidly developing nuclear technology. Marsden, who gave up his position as Secretary of the Department of Scientific and Industrial Research during the war years to become Scientific Liaison Officer at London, provided the stimulus needed to encourage younger scientists to study nuclear science. Just prior to the war, Marsden had encouraged a young New Zealand physicist, C. Watson-Munro, to make a re-evaluation of the radioactivity of New Zealand soils and rocks, again in an attempt to discover any correlation between high radioactivity and the incidence of goitre. Through Marsden's efforts, Watson-Munro in 1945 led a group of physicists and engineers to work on the development of nuclear reactors, first, at Chalk River in Canada and, later, at Harwell, England.
During the war years in New Zealand, work on the geology of uranium and thorium minerals had been undertaken mainly by C. O. Hutton, of the Geological Survey, and on the chemistry of these elements by F. T. Seelye and T. A. Rafter, of the Dominion Laboratory.
In January 1946, Cabinet first considered the possibilities of establishing a group of scientists in the D.S.I.R. to undertake nuclear research and, in the following August, Marsden was asked to inquire whether artificially produced radioactive elements would be available for analytical and research experiments. Ultimately in June 1947 the first artificially produced radioactive material, produced in the cyclotron of the Carnegie Institute of Technology, was forwarded to New Zealand with the request that separation from the target radioactive iron, cobalt, and manganese should be carried out, and these isotopes be made available for tracer studies in soil science.
On 3 June 1947, a meeting was held at the Dominion Laboratory to consider the problem of handling radioactive substances. It was agreed that the physical laboratory would supply measuring equipment, and attempts were made at organising procedures for the safe handling and storage of radioactive materials. The radioactive iron, cobalt, and manganese extracted from the target were to be handed over to N. H. Taylor and Dr Strzmienski of the Soil Bureau for iron fixation studies in soils, and for cobalt and manganese deficiency experiments in plants. The first nuclear-reactor-produced radioactive isotopes arrived at the Dominion Laboratory on 4 July 1947. This was radioactive phosphorus produced by the irradiation of “Fos-Cop” solder consisting of 5 per cent P and 95 per cent Cu, the phosphorus being in the form of yellow ammonium phospho-molybdate. The phosphorus was converted into the form of phosphate fertilisers for the first phosphate fertiliser pot experiments.
On 19 September 1947, Cabinet empowered the Secretary of D.S.I.R. to convene a meeting between representatives of D.S.I.R., Health, and Agriculture Departments to ensure the safe and orderly use of radioactive isotopes in New Zealand. The outcome was the drafting of the X-Ray and Radioactive Substances Act which is now administered by the Dominion X-Ray and Radium Laboratory.
In 1947 C. N. Watson-Munro returned to New Zealand through America and made arrangements for a chemist to study at the Radiochemical Centre at M.I.T. Boston, and the Mass Spectrometer Laboratory of Columbia University, New York. T. A. Rafter, who was selected for this work, left New Zealand in August 1948 to study nuclear chemistry and, after visiting nuclear establishments in America, Canada, and England, returned to New Zealand in October 1949.
C. N. Watson-Munro, then an Assistant Secretary of D.S.I.R., and Sir E. Marsden, then New Zealand's scientific adviser in the United Kingdom, with the support of J. D. Cockcroft, advised the New Zealand Government on the feasibility of constructing in this country a low-energy atomic pile. At that time New Zealand had 10 highly trained physicists and engineers, including C. Dalton, who became director of the Australian Atomic Energy Establishment, R. M. Williams, later director of Applied Mathematics Division of D.S.I.R., and I. K. Walker, director of the Dominion Laboratory. The plan for construction of the reactor did not receive final Government approval, and this group of scientists broke up to become leaders in other countries or in other branches of science.
From 1949 to May 1955 a small group of physicists at the Dominion Physical Laboratory and chemists at the Dominion Chemical Laboratory worked in close cooperation in an endeavour to introduce some of the newer techniques of nuclear science into New Zealand's scientific problems. Radioactive phosphorus was used in fertiliser trials first by R. E. R. Grimmett of the Soil Fertility Station, Hamilton, in September 1950, while D. W. Urquart was the first to use radioactive phosphorus for medical therapy at Palmerston North in February 1955. Radio-iodine for the treatment of thyroid disorders and isotopically enriched nitrogenous fertilisers in plant experiments were other experiments in which the small nuclear science group participated. A radioactive survey, using modern electronic equipment, was made of the thermal areas, and a method for the ageing of carbonaceous specimens by their radioactive carbon content was perfected. By June 1955 the group of physicists and chemists combined to form the Isotope Division of the Dominion Physical Laboratory, and by June of 1957 had become a separate Division of Nuclear Sciences of D.S.I.R. under the director, T. A. Rafter, and was housed at Gracefield, Lower Hutt.
As nuclear science had expanded within D.S.I.R., so also had progress been made in the universities. Research in nuclear physics was being sponsored in all four university colleges. At Otago University, under R. R. Nimmo, a low-energy 800 kev. Van de Graaff accelerator had been constructed. At Auckland University, first under P. W. Burbidge and, later, under D. Brown and E. R. Collins, a vigorous nuclear research programme was initiated. A 600 kev. Cockcroft-Walton accelerator was constructed and used for a variety of experiments in which the emphasis has been placed on the study of the polarisation of nucleons emitted following nuclear reactions. In the chemistry department, D. Llewellyn and A. L. Odell have built up a strong department, using radiochemical and mass spectrometric techniques for training and research.
Nuclear science was becoming a specialised field of interest both to Government scientists and to universities. Towards the end of 1957, the Government and the University of New Zealand invited two distinguished Australian scientists, Leslie H. Martin and J. P. Baxter, to advise on the development of nuclear science training and research in New Zealand. This visit was closely followed by a visit from a United States Atomic Energy Mission, headed by R. K. Kirk. The result of these visits was that Cabinet, on 3 June 1958, approved the establishment of an Institute of Nuclear Sciences, as a branch of D.S.I.R. to be administered by the Department in collaboration with the University of New Zealand. It also recommended the appointment of an Atomic Energy Committee, the preparation of plans for the Institute, and the purchase of a 3 Mev. proton-electron Van de Graaff accelerator as the first major nuclear machine for the Institute. In May 1959, the Public Service Commission appointed T. A. Rafter director of the Institute of Nuclear Sciences. Negotiations for the site of the Institute were necessarily prolonged. It was finally decided to develop the Gracefield site, near Wellington, and Cabinet approved the expenditure of £374,000 for the establishment of the first stage of the Institute.
by Thomas Athol Rafter, O.B.E., M.SC., F.R.S.N.Z., Director, New Zealand Institute of Nuclear Sciences, Department of Scientific and Industrial Research, Lower Hutt.