My grandfather, Stefanus Jakobus Du Toit (who had the exact same name as I do), is likely the first nuclear physicist from South Africa. I was recently sent this relatively short autobiography of his, originally written in Afrikaans, from his daughter (and my aunt) Johanna van der Walt (néé du Toit). I’ve translated it into English, with editing help from my aunt, attempting to remain as close to the original style as possible. I think it provides a fascinating look into someone who undoubtedly contributed greatly to the use of atomic energy in South Africa, both for peaceful and military purposes. I’ve tried to sprinkle links along the way that may provide some more detail or modern context. Additions in [square brackets] are my own, as well as any images. Enjoy!

In December 1936, I completed my schooling in Boshof. Physics was not offered there, despite it being one of the leading high schools at the time. (Perhaps this was a lucky break, because the science courses offered were such that they removed all interest in the topics from those taking them!) My chemistry teacher still maintained, in 1936, that the smallest unbreakable part of matter was the atom — despite Rutherford having split atoms as early as 1919! In university, I performed poorer in chemistry than I did in physics — despite not having taken physics in high school.

A photo of my grandfather, undated — copyright holder unknown

Coming to university was a wonderful experience. When I sat in professor Van Wageningen’s class for the first time, I thought: “Well that’s how a lecturer should look!” Prof. Van Wageningen took out a giant Meerschaum pipe, calmly stuffed it, and then proceeded to disappear behind a thick cloud of smoke from which only his voice emanated. He never dictated lectures, saying that the dictation of lectures dated back before the invention of the printing press. Since the press had already been invented a few centuries back, and students at the university were expected to be able to read, he instead prescribed quality textbooks, from which a certain number of pages were to be read per day. At the next class students were expected to ask questions about anything they found unclear. If there were no questions, he would simply state something like, “read the next six pages of Duncan and Starling”. Such a class might sometimes only last a couple of minutes. So it went on, until we we suddenly realized that a test was coming up! Then suddenly the questions began to rain down upon Prof. Van Wageningen and the time available to ask them in lectures now seemed too short. Every physics lesson was now marked by lively discussion!

This method of lecturing taught me a very important lesson: never accept a claim and memorize it unless you thoroughly understood it and were convinced of its correctness!

From Potchefstroom, which lacked the laboratory equipment to offer a MSc degree, I moved to Stellenbosch, where Dr Meiring Naudé had recently opened the magnificent new Merensky Institute of Physics (at the time still spelled “Fysika” in Afrikaans, rather than the current “Fisika”). With 9 students, we were one of the biggest MSc classes studying physics together in South Africa!

At the time (1941–1942), nuclear physics was still a very small part of physics overall. It wasn’t part of our curriculum at all, and the library had a mere one or two textbooks dedicated to it. The closest a student could get to studying nuclear physics on their own was to read through the books on radioactivity and one or two short books on cosmic radiation. Nuclear physics was, however, interesting to me, so I started researching original papers on the topic in physics journals. As my MSc assignment, I chose to build a cloud chamber.

“Beta radiation detected in an isopropanol cloud chamber” — photo by Nuledo, CC BY-SA 4.0

After I received my MSc degree, I was employed at Potchefstroom as a Lecturer in Nuclear Physics and Applied Sciences. Shortage of equipment was a major, consistent limitation. During holidays in the Karoo I collected donations from well-off wool farmers. Those cheques were deposited at the registrar’s office, where they were matched pound for pound, doubling the contributions. Useful equipment for research was acquired slowly but surely. I registered as a DSc student at the university of Stellenbosch. I spent my long vacations at the Merensky institute. Later I was able to continue my research work in Potchefstroom. I had to pay for my own tickets to travel between Potchefstroom and Stellenbosch. I was only able to get some financial aid to pay for the tickets once the CSIR [Council for Scientific and Industrial Research] was established in 1945.

In 1946 the National Physics Laboratory (“Nasionale Fisiese Laboratorium”, NFL) was founded, with Dr Meiring Naudé as its first director. I was appointed as the Department Head for Radioactivity, and assumed my post on April 1, 1947.

Dr Meiring Naudé — photo from StellenBoschWriters.com

The first task in the radioactivity department was to develop equipment to detect radioactive materials. The uranium trade at the Rand was developing quickly and at the time one couldn’t just obtain a Geiger-Müller detection tube from suppliers. The uranium ore from Witwatersrand was of low concentration and hard to measure accurately. It was also important to understand whether the uranium and radon posed health risks for the mine workers.

Witwatersrand National Botanical Gardens — photo by Chris Eason, CC BY-2.0

Early in 1948, I began the last experiments necessary to complete my DSc thesis. This allowed me to aim for a final completion of all requirements of the degree by the end of August. One morning, the founder and president of the CSIR, Dr B.F.J. Schonland, asked Dr Naudé and me to visit his office. I was highly surprised when he told me [in English], “Du Toit, I want you to become South Africa’s first nuclear physicist. I am sending you to the Nuffield Institute in Birmingham for two years of postdoctoral study and research”. When I left his office I felt like I was floating!

Sir Basil Schonland — copyright holder unknown.

The Nuffield laboratory was a big disappointment. The place was awfully dirty and dishevelled. The head of the department, Prof. Marcus Oliphant, had about 40 postgraduate students, all of which were hoping to earn a doctorate. The group was unbelievably unproductive and between all of them didn’t publish more than two or three papers per year. A small group of postgrads under Prof. P.B. Moon, in fact, produced just as many publications! I was interested in Prof. Moon’s work. He had explained that it concerned a new branch of nuclear physics, namely nuclear spectroscopy.

I started an intensive study of nuclear spectroscopy in the library and quickly came to the conclusion that there was one group leading in the research area internationally: the group of researchers led by the young professor Kai Siegbahn at the Nobel Institute of Physics [I believe my grandfather is referring to the Physics Department at the KTH Royal Institute of Technology] in Stockholm. I approached the CSIR about a transfer to Stockholm. Around this time, Dr. AJA Roux visited us for a weekend. After he saw the state of my office (which I shared with two Australians, and was never cleaned during the 5 months I worked there!) he took it upon himself to send my proposal to Dr Naudé and Dr Schonland! Shortly after I received permission to move to Stockholm.

What a difference! The neat and tidy Nobel Institute contained excellent equipment, like a large cyclotron, several beta ray spectrometers, and a machine for separating isotopes. Around 15 researchers worked under the leadership of Prof. Siegbahn, producing about 30 publications per year!

In Stockholm I became thoroughly convinced that nuclear spectroscopy was the ideal choice for a South African research direction. The equipment necessary wasn’t extravagant or beyond South Africa’s financial means. The main instrument in such a program would be a medium-sized cyclotron. Building such a cyclotron thus became priority number one of the Nuclear Physics Department of the CSIR. We employed the services of a young and proficient electrical engineer, Dr. Cor Kritzinger. The CSIR accepted my request that he join me in Stockholm and also to allow him, after my departure from Stockholm, to spend 6 months at MIT in the USA to develop the first South African cyclotron (in fact, the first in the southern hemisphere) under Prof. Livingston. Livingston, who together with Lawrence developed the first cyclotron in the world, was well known as the world’s foremost expert on cyclotrons at the time. The Pretoria cyclotron’s construction was completed in 1956 and it began production two years later.

The Pretoria cyclotron during construction, with my grandfather shown third from the right. — from Scientiae 1988/4.

The Pretoria cyclotron in operation — from Scientiae 1988/4.

The idea behind the Department of Nuclear Physics was to serve as a national research centre for nuclear physics. The equipment needed for nuclear physics was too expensive to equip every, or even a single, research group at South African universities such that they could perform research at an international calibre. The idea was to have the CSIR, in its Nuclear Physics Department, create the necessary environment, and to allow students interested in nuclear physics from any university, after obtaining their BSc. (Hon.) or MSc. there, to register as DSc or PhD students and perform their experimental work at said Department at the CSIR.

We employed the services of two brilliant nuclear physicists from Europe: Dr. Helmut Schneider from Switzerland, and Dr. Willi Frahn from Germany, to help teach the doctoral students. The CSIR, together with the Atomic Energy Board, made scholarships available for postgraduate students. Some of the students receiving those scholarships later played an important role in the scientific world of South Africa. I am thinking, among others, of Dr J.W.L. de Villiers, Dr D. Reitman, Dr C.A. Engelbrecht, et al.

In the meantime, the importance of atomic energy increased. In 1957, the CSIR asked Dr A.J.A. Roux, director of the National Institute of Mechanical Engineering, to start a program for atomic energy in South Africa. With this in mind, he visited nuclear power plants in the US, Canada, and Western Europe. He asked me to accompany him to cover the purely scientific aspects of nuclear energy, while he concentrated on the engineering and other concerns. In October of 1957, Dr. Roux returned to Pretoria while I traveled to CERN in Geneva. I completed my report and mailed it to Dr. Roux.

In 1958, the Atomic Energy Board (AEB) accepted Dr A.J.A. Roux’s programme, and sent it to the government for approval. Dr. Naudé held the opinion that the programme needed to be implemented by the CSIR, while Dr. Roux felt that the AEB, up until that point a purely administrative agency, needed to be expanded to take care of the task. The government chose the AEB. Dr. Roux was employed as the Director General of the AEB and started expanding its framework to a full-fledged national organization for nuclear energy.

The result of this decision, unfortunately, had negative consequences for the Department of Nuclear Physics at the CSIR. Everyone’s attention was now on the AEB. Although nuclear physics formed the basis upon which nuclear energy was based, enough basic knowledge was available at that point to act as the foundation of an industrial program for nuclear energy. Some of the heads of the Department of Nuclear Physics applied for employment at the AEB. Dr. Roux offered me the job of the head of the Physics Department of the AEB, and I accepted. My family and I were sent to Argonne National Laboratory in LeMont in the US for 16 months in 1960, where I ran nuclear experiments using a neutron bundle from the research reactor. Part of my time was devoted to the study of neutron physics.

My grandfather’s certificate for training at the Argonne National Laboratory — from family files.

Back in South Africa, just in time for Republic Day, we worked very hard to plan and build a research centre on a barren field near Pelindaba, west of Pretoria. The Physics Department of the AEB was closely linked with the physics departments at our universities. The AEB made significant donations to support projects related to nuclear energy. We supported students with scholarships, both in South Africa and internationally.

“Pelindaba as viewed from the north in 2006” — photo by Wikipedia User NJR ZA, CC BY-SA 3.0.

Filled with the spirit of optimism of the new republic, and with a thoroughly sympathetic and intelligent Prime Minister in the form of H.F. Verwoerd, the development of Pelindaba progressed quickly. The Physics Department of the AEB developed an active research program in neutron physics around its Van de Graaff accelerator.

Visiting the Pretoria cyclotron on its 25th construction anniversary (likely ca 1980). My grandfather is on the very left, accompanied by all later heads of its operation. — from Scientiae 1988/4

Since my school days I had developed a great preference for the metric system of measurements. At university it was wonderful to, at least in the laboratory, work with the centimeter-gram-second system of units. In Stockholm it was extremely pleasant to live in a metric country, where even daily concepts like rainfall, atmospheric temperature, distances, volumes, etc. were expressed in the metric system. When we developed the cyclotron, we decided that all the design work would be done only in metric units. The designs we sent to industry were thus purely metric, which they had no problem following at that point.

When the government decided that South Africa would switch to the metric system, a special Department of Metrication was created within the South African Bureau of Standards (SABS) to lead the changeover. When the SABS was looking for someone to lead this department, I applied for the post, and was employed as Director of the Department of Metrication in April 1969.

One of the most interesting and happy periods of my life followed. Metrication connected me to every imaginable activity in the country, as there is no household, business, or any economic activity where something doesn’t need to be measured! I spoke at many conferences, from professional associations to housewives’ clubs.

The process of switching progressed so well that it led to the Law of Measurements and National Measurement Standards [in Afrikaans, Wet op Meeteende en Nasionale Meetstandaarde] in 1973. With that, the changeover program was completed. The original estimate of the Louw committee, which researched the desirability of the switch to the metric system, was that the entire process would take 15 years — till 1984. I believed that it would keep me busy until my planned retirement in 1979. In light of the new circumstances, I chatted with Dr A.J.A. Roux about a possible posting at the AEB. He informed me that there was a fitting vacancy at the Uranium Enrichment Corporation [In Afrikaans, Uraanverrykingskorporasie, or UKOR], which had been spun off from the AEB in the meantime. I experienced the last five years [of my career] at UKOR as Assistant General Manager.

The final paragraph of my grandfather’s original Afrikaans autobiography and his signature — from family files

S.J. Du Toit, 1996–12–18