University of the Witwatersrand Physics Department

University of the Witwatersrand Physics Department – See Details Below:

About us

Compiled by Arthur Every, with contributions from Frank Nabarro, Mike Witcomb, Silvana Luyckx, Mike Hoch, Dave McLachlan, Gio Hearne, Dieter Heiss, Balt Th Verhagen, Mike Stanton, John Carter, Darrell Comins, James Larkin and others

Wits University traces its roots back to the South African School of Mines, which operated in Kimberly from 1896 to 2003, and moved to Johannesburg as the Transvaal Technical Institute in 1903. It went through a series of name changes, starting with the Transvaal University College (1906-1910), then the South African School of Mines and Technology (1910-1919) and the University College Johannesburg (1919-1922), before finally receiving its charter as the University of the Witwatersrand in 1922.

The first Professor of Physics appointed to the TUC was R A Lehfeldt. Probably the most important research achievement during his tenure was the accurate measurement of the acceleration of gravity on the Highveld, which supported the theory of isostasy. Lehfeldt’s successor, Alexander Ogg, was Professor of Physics as well as Acting Principal for three years only, 1917 – 1920. He had come from the Chair of Physics at Rhodes University College, and after his short spell in Johannesburg, left to take up the position of Head of the Department of Physics at the University of Cape Town.

Ogg’s successor Henry Howard Paine, was appointed in 1920, and he was soon joined by his fellow Welshman G T R Evans. In the Old Tin Temple premises off Eloff Street occupied by the Physics Department at the time, Paine and Evans were the only staff, and they had an annual grant of 200 pounds to cater for about 100 students. By 1925 in the new Milner Park campus they had expanded to about 250 students, a total of 4 academic staff, and one instrument maker. Paine held his position as Head of Physics at Wits until 1946, and died in 1980 in his 97th year. He remained a teacher in the department until only a few years before his death. Paine had studied under J J Thompson in the Cavendish at Cambridge, and his neatly compiled lecture notes of 1905-6 and a letter from Thompson survive. He had a strong interest in the history of physics and chemistry in the United Kingdom, and left a specialized collection of books in this field and a considerable sum of money to the library, from which the H H Paine Collection has grown.

Evans succeeded Paine in 1947, but died suddenly in 1950, and M A Cooper was acting head until 1953. A notable member of staff in this period was Doris Kuhlmann-Wilsdorf. She joined the Department in 1950 while her husband Heinz became the first electron microscopist at the CSIR. They jointly published a number of papers on electron microscope investigations on pure aluminium, and dislocations in aluminium-copper alloys. In 1956 they relocated to the University of Virginia, but maintained close contact with their South African colleagues over the years. Another notable person at Wits in those years was Eric C Halliday, who joined the Department in 1926 as a lecturer. Between 1933 and 1935 he worked at Cambridge under C T R Wilson and E V Appleton, and on his return to Wits he set out to study lightning and the Heaviside layer. He was one of the first to show the existence of multiple lightning flashes. In 1945 he was appointed to the newly founded CSIR by its first President, Basil Schonland, and subsequently had a distinguished career in the NPRL. D J Malan was another early member of the Department who contributed to the study of lightning. H J Logie, who did his Hons in Physics at Wits in 1939, became a junior lecturer in 1940. After serving in the forces, Logie resumed his academic career in 1946. Despite the heavy teaching duties which the staff undertook on account of the very large number of ex-Servicemen returning to South Africa, he took part in an active research programme on earth tremors, obtaining a PhD in 1949 for a thesis on this work. In 1950 the Department decided to form a team working on the field of metals, and Logie spent a year studying the physics of metals at the University of Birmingham. On his return, as the first occupant of the newly founded Chair of Experimental Physics, he embarked on the study of the effects of plastic strain and the electrical properties of counting diamond. He died in 1958 at the age of 39.

Frank Nabarro’s Arrival and Later Years

With the arrival of Frank Nabarro as Head of Department in 1953, research was given a much higher priority than hitherto. Schonland was instrumental in recruiting Nabarro to Wits. Within a few years of his arrival, Nabarro had built up the Department to considerable strength. Wladimir Brommert became Nabarro’s right hand man, taking over much of the administrative burden of the Department and freeing Nabarro for more creative pursuits.

Interestingly, although Nabarro did establish a group working with him on the mechanical properties of solids, he did not seek to turn the department into an empire focused entirely on his area of expertise. On the contrary, through successful hiring he encouraged the diversification of the department into magnetic resonance spectroscopy, low temperature physics, optical spectroscopy and theoretical physics, and he oversaw the creation of the Electron Microscope Unit. With the appointment of Friedel Sellschop as director of the Nuclear Physics Research Unit (NPRU) in 1956, one saw a major thrust of the department into Nuclear Physics open up. Nabarro and Sellschop were both extraordinarily talented and strong willed individuals, and it was almost inevitable that the Physics Department would prove too small to contain both of them. In 1969 the NPRU became an independent entity.

Nabarro served Wits University in various capacities, including a term as Deputy Vice Chancellor. During his tenure in that position, in 1981 he drew up the Academic Plan, the first for any South African University, which anticipated and planned for a large influx of black students. He retired in 1984, but remained an active member of the Wits community. He played a prominent role in the SAIP and a number of other scientific organizations in South Africa. He was a Fellow of the Royal Society of London and a Foreign Associate of the US Academy of Engineering, the only one on the African Continent, and was the recipient of numerous awards.

In 1977 Nabarro was succeeded by J H N (Jan) Loubser, who had been appointed to the Chair of Experimental Physics at Wits in 1962. Loubser had earlier been one of the signatories of the proposal that eventually let to the establishment of the SAIP.

Mike Hoch followed as HOD in early 1982, and held that position until 1994. During the late 1980s and early 1990s considerable effort was devoted to assisting the Schonland Centre overcome budgeting difficulties. These efforts helped bring experimental nuclear physics closer to the Department. The permanent chair structure in the second half of the 1980s comprised Theoretical Physics, Experimental Physics, Nuclear Physics and Solid State Physics. The two ad- hominem chairs were held by Richard Lemmer and David McLachlan. Darrell Comins and Arthur Every were later promoted to ad hominem chairs.

Darrell Comins was Acting Head from April 1994 and HOD from 1995 to 1997. During this period the democratic process of managing the Department was further extended through the Advisory Committee and other means. New directions were established including high pressure physics and nanoscience. With the appointment of Sellschop as DVC (Research), a Search Committee was constituted for a new Director for the Schonland Centre. This process proved unsuccessful, and a totally new structure was proposed, in which there would be a Governing Committee consisting of the Leaders of the respective Research Groupings. In order to relieve existing budget constraints, staff members of the Schonland were offered academic positions in appropriate Departments.

Barry J Cole served as Head of Department and then School from 1998 to early 2006, a period of dramatic restructuring and devolution in the University. The new structures came into being at the beginning of 2000. The Science Faculty retained its separate identity and the Department of Physics was deemed sufficiently large to be transformed overnight into the School of Physics. However, the consequent devolution of many University systems, functions and responsibilities impacted greatly on the Faculty and School. Many activities that had previously been the responsibility of the central administration were transferred to the Faculty, and Faculty functions devolved to the Schools.

More or less coinciding with these changes was a significant change in the way in which the University funded research. Hitherto, research groupings were recognized by the University Research Committee, who then annually allocated them funds to carry out their research programmes. In addition, the Research Office administered the research incentive scheme. Under the new scheme, 70% of the University’s research money was distributed to the faculties according to their research and graduate student outputs averaged over the previous three years. Unfortunately, the new funding model took no account of the fact that some research activities were much more expensive than others, and the research funding to the Science Faculty dropped dramatically. Consequently, many activities in the Faculty were no longer financially viable; one victim of this cut in funding was the Schonland Institute for Nuclear Sciences, whose infrastructure and support staff were transferred to the NRF as a national facility. In addition, the Materials Physics Research Institute was no longer able to fund its research support staff.

Since the beginning of 2006, Jo Rodrigues has been Head of School, with John Carter as his deputy. One of the more challenging problems he faces is the recruitment of young research active staff to replace the many senior staff members who have retired in recent years. Of note, Robert de Mello Koch has been awarded a DST-NRF Research Chair.

The Solid State Physics Research Unit and its Successors

Nabarro was a great champion of experimental physics. When he was negotiating to come to Wits, his primary concern was what experimental facilities there were, and what funding there would be from government and industrial sources for experimental research. The Solid State Physics Research Unit (SSPRU) was established in 1961 with Nabarro as director. Its purpose was to coordinate research activities sponsored by the University, the CSIR, Hard Metals Ltd., De Beers DRL and ISCOR. From the outset, the Unit’s activities were divided between basic physics and projects having a direct bearing on the South African economy. There were originally three main fields of research: the fracture of quartzite, which was largely carried out by H. Schlon and Tony Ball and research students Ludwig Schog and Hayd le Roux, the strength of hard metal alloys, particularly WC-Co, which was mainly driven by Silvana Luyckx, and diamond physics. The SSPRU evolved over the years into what is now called the Materials Physics Research Institute (MPRI), and has left its genetic imprint on the DST/NRF Centre of Excellence in Strong Materials.

With Nabarro’s retirement at the end of 1984, the SSPRU, was closed down in line with University policy. Out of its ashes the Condensed Matter Physics Research Group (CMPRG) was established in January 1985, with Mike Hoch as Head and with a greatly reduced research budget compared to the SSPRU and no research staff positions. Over the years the CMPRG established itself as a vigorous and productive entity. On review in 1990, it was elevated to research unit status. The Unit prospered through the 1990s and in 2000 the significant achievements made by members of the Unit were recognized through the granting of research institute status. Following Michael Hoch’s retirement at the end of 2001, David McLachlan became Director followed a year later by Darrell Comins who held the position until his retirement at the end of 2007. Membership of this collective has changed a lot over the years with new appointments, retirements and the passing of a number of individuals. Recent recruits include Marjorie Mujaji, Karin Pruessner, Jonathan Keartland, Sanjiv Shrivastava and Somnath Bhattacharyya.

The study of materials is by no means confined to physics. It cuts across the boundaries of many of the sciences and branches of engineering. Thus, members of the Physics Department have been drawn into a number of wider structures, most notably the DST-NRF Centre of Excellence in Strong Materials . This collective brings together a unique team of materials scientists, drawn not only from Wits, but also from the Universities of Johannesburg and Kwazulu-Natal, NMMU, MINTEK and NECSA. It has strong interaction with local industry. Darrell Comins directed the Centre from its inception in 2004 until mid 2007.

Materials Research

The main areas of materials research at Wits over the years have been the following:

Electron Spin Resonance (ESR). ESR at Wits is inseparably associated with the name of J H N (Jan) Loubser. He started off at Stellenbosch University and UCT, from where he proceeded to Oxford on a Rhodes Scholarship, to do research on microwave spectroscopy of gases for his D.Phil.. From 1948 to 1949 he held a postdoctoral fellowship at Columbia University, where he worked with the future Nobel Laureate Charles Townes. He returned to South Africa to work at the CSIR and then in 1953 to take up the Headship of the Department of Physics at UOFS. In 1962 he was appointed to the Chair of Experimental Physics at Wits. In order to support the Department?s existing interest in solid state physics, he switched his research from microwave spectroscopy of gases to ESR. With students and long time colleague Jan van Wyk and other collaborators, he applied ESR methods to the study of paramagnetic defects in diamond. This activity was started partly because of ready access to samples through contacts with De Beers Diamond Research Laboratories (DRL). This work had a fundamental focus related to the fact that diamond is a very special wide gap semiconductor, and also a practical goal of importance to the gem trade, since ESR is a valuable tool in the identification of the colour centres that accompany irradiation and annealing. Loubser passed away in 1994.

Nuclear Magnetic Resonance (NMR). NMR has been driven by Mike Hoch, who joined the Wits Physics Dept. from Natal University 1970. In the early 1970s a 1.2 Tesla 12 inch high homogeneity Varian electromagnet was acquired for NMR research on condensed matter. With the assistance of Roy Day he pioneered EPR imaging using an X-band EPR spectrometer, modified to have static magnetic field gradients, that could be rotated with respect to the sample cavity. The first EPR images ever recorded, showing spatial resolution of small DPPH crystals and also of two small diamonds, were obtained at Wits.

During a sabbatical year spent at Cornell in 1986-87 Hoch became involved in metal-insulator work on heavily doped semiconductors. The work was continued at Wits with postgraduate students using the dilution refrigerator. In collaboration with Johan Prins at the Schonland Centre, a project on the metal-insulator transition in single crystal diamond was carried out using high purity single crystal diamond implanted with boron ions, permitting a detailed study of the transition. A number of experiments on the Group V semi-metals was also carried out in this period using NQR methods at high pressure. In the mid-1990s an X-band Bruker spectrometer was purchased and located at the De Beers Diamond Research Laboratories for three years, where it was used for various experiments, and was later transferred to Wits. At this time a 5 tesla wide bore superconducting magnet was acquired from Sasol who no longer needed it. At Wits considerable effort was devoted to developing ¹³C dynamic nuclear polarization methods in type Ia and Ib diamond combining EPR and NMR facilities. Hoch retired at the end of 2001. At present the NMR lab is managed by Jonathan Keartland.

Low Temperature Physics. This was initiated in 1965 by Professor Frank Nabarro, on the grounds that low temperature measurement facilities were essential to a modern solid state research laboratory. At that time a problem of particular interest to him, was that of the interaction between crystalline dislocations and the vortex lattice in a type II superconductor.

Helium, hydrogen and nitrogen liquefiers were acquired from Oxford University, and housed in the so-called ?Low Temperature Laboratory?, which was run under the guidance of Paul Jackson. John Watts was hired to get the plant operational and was assisted by two new graduate students, Wally Kopp and Ewald Wessels. After many trials and tribulations the team finally succeeded in making the first liquid helium in South Africa, about one litre of it, in 1964. In 1968 a second hand Collins Model 10 Liquefier was installed in the LTL, and became the work horse of low temperature physics at Wits. Darrell Comins was one of the first to publish on work done with this liquid He at Wits.

Two graduate students were taken on by Nabarro, Terry Doyle to work on the experimental aspects of fluxoid dislocation interactions and Alex Quintanilha to assist him in the theory. Barbara Rothberg worked on the effect of elastic strain on the superconducting phase diagram of super-elastic tin whiskers. Two returning South Africans were recruited, John Brock, an Oxford graduate, who had just completed a post doc in California and David McLachlan who, after graduating in the States had worked at the IBM Zurich Research Laboratory for four years. With their arrival a modern low temperature laboratory was set up. It included a He³ cryostat and facilities for low temperature thermal conductivity and for high sensitivity susceptibility measurement. In separate laboratories Terry Doyle installed facilities for low temperature magnetic measurements (including a very sensitive, in-house built, vibrating sample magnetometer with a 5T superconducting magnet) and Barbara Rothberg had installed a precision micro-straining device for her tin whisker research.

The earliest publications from the ‘low-temperature group’ were due to McLachlan who, succeeded in observing (for the first time recorded) the quantization of the fluxiod. Brock established a research programme on the measurement of the low temperature thermal conductivity of solids, particularly diamond samples supplied, cut and polished by de Beers. Jan W Vandersande joined Brock as a graduate student in 1969, and over a number of years, first as a student and then as a member of staff, was engaged in correlating the conductivity of insulating solids, particularly diamond, with the presence of impurities and other point defects, dislocations and boundaries. Jean Paul Burger visited the department in 1972 and he and Mclachlan worked on magnetic alloys of PdMn variously doped with atomic hydrogen. Unknowingly they made some of the first observations on spin glasses at low temperature, the original publications in this field appearing shortly before their joint paper.

In 1980 the increasing need for liquid helium in the department and in other universities in South Africa necessitated a new Helium liquefier and a C.T. liquefier was purchased from Afrox, who had found that the commercial market would not support such a plant. This was installed in 1981 and produced sufficient liquid Helium for the departments and other needs, including the first medical MRI scanners in the late 1980s. Experience with this liquefier enabled the departmental team, consisting of Hoch, Kolk and McLachlan and Peter Ford motivated for the purchase of a He³ dilution refrigerator.

With the advent of High T_c Superconductivity, in 1987 McLachlan and Richard Doyle joined the University of Natal and the CSIR to form a team, sponsored by De Beers Industrial Diamond Division to try to develop new, higher operating temperature materials using De Beers high pressure know-how, but this effort was not too successful. In order to encourage activities in the low temperature physics area a Workshop on Low Temperature Physics was held in 1989 with Bob Richardson of Cornell University as an invited speaker. It served as the official inauguration of the dilution refrigerator. The proceedings of the Workshop were published in the SA Journal of Physics. In 1991 a Theoretical Summer School on Low Temperature Physics was held at Blydepoort. The proceedings were edited by Hoch and Lemmer, and published by Springer. Two of the speakers, Tony Leggett and Bob Richardson, were later awarded the Nobel prize. Dr Vladimir Gridin joined the department in 1990, and published on high T_csuperconductivity, magneto-transport, and heat capacity measurements.

Optical spectroscopy of solids. This was initiated by Leon Vermeulen in the early 1960s with work on the optical properties of diamonds. He, Roger Farrer and Alun Harris published on a number of aspects of diamond physics, including counting properties, photoconductivity, defects, magnetoresistance and Hall currents. P T (Pete) Wedepohl joined the Department in 1964, and initiated the then ?hot topic? of radiation damage and colour centres in alkali halides, using optical absorption spectroscopy, with Darrell Comins as his Ph D student. Wedepohl also conducted first principles calculations on defects.

In his career spanning 42 years at Wits, Darrell Comins together with a number collaborators and postgraduate students, has built up optical spectroscopy of solids into one of the major fields of research at Wits, with world class experimental facilities, including the Wits-NRF Raman and Luminescence Laboratory, a National Facility that provides service to academics in various disciplines and also a number of industrial users. His research has encompassed several distinct areas: radiation damage and ion implantation in various materials with A Allen, J Marat-Mendes B Carragher, T Derry, A Davidson (Zululand), S Connell, M Naidoo and G Amolo; fast-ion conductors studied by high temperature Brillouin and Raman spectroscopy with P Ngoepe, P Mjwara, C Anghel, E Rammutla and M Mujai; ambient and low temperature Raman and luminescence spectroscopy of diamond with M Fish, S Bradlow, J E Lowther and R Erasmus; site selective spectroscopy with M Mujaji; surface Brillouin scattering (SBS) at ambient and high temperatures as well at high pressure with A Every, P Stoddart, W Pang, X Zhang, J Crowhurst, G Hearne, S Tlali, B Mathe and C Sumanya; high pressure Raman studies of nanomaterials with G Hearne, M Nieuwoudt and R Erasmus; high temperature studies of carbon nanotubes with R Shiri and R Erasmus; metallic corrosion studied in situ by Raman spectroscopy with M Nieuwoudt and E M Sherif. His major collaborators abroad have been W Hayes and R Harley (Oxford), R Catlow (Royal Institution), A Chadwick (Kent), S Lefrant and E Rzepka (Nantes), E Balanzat (Caen), N Kristianpoller (Tel Aviv) G Saunders and E Macdonald (Bath), K Schwartz and C Trautmann (Germany), B Hillebrands, T Wittkowski and K Jung (Kaiserslautern) and L Hobbs (MIT).

f-Electron Magnetism and Heavy Fermion Research Programme. Paul de V. DuPlessis joined the Physics Department from RAU in 1993, taking up the Chair of Experimental Physics. He formed the f-Electron Magnetism and Heavy Fermion Research Programme, in which he was joined by his research assistant Andre M Strydom. The research they conducted over the years, much of it with Polish collaborators R Troc and D Kaczorowski and F Steglich in Dresden and postdocs M B Tchoula Tchokonte, L Menon and V H Tran, was mainly concerned with the magnetic and transport properties of rare earth compounds, holmium and dysprosium or otherwise heavy Fermion compounds. Kondo behaviour and antiferromagnetic transitions are some of the issues that came up. Most of their measurements were done in-house in their lab at Wits, but their measurements with neutron scattering had to be done elsewhere. DuPlessis retired from Wits in 2005, and he and Strydom are now at UJ.

Electron Microscopy. The history of electron microscopy at Wits is closely associated with the name of John W Matthews. In 1956, having just graduated with an honours degree in physics, he was appointed Laboratory Assistant in the Department of Physics, and given the responsibility for the installation and supervision of the second transmission electron microscope (TEM) to be purchased in South Africa, the first being at the CSIR in Pretoria. Matthews was largely responsible for the maintenance of the microscope, while being encouraged to create an interest in electron microscopy throughout the University as well as develop his own field of research. The presence at the CSIR of J T (Koos) Fourie, who had experience in the electron microscopy of thin metal films, and J H van der Merwe at the University of Pretoria, a pioneer in the theory of epitaxy, induced Matthews to work on the electron microscopy of epitaxial deposition. In time he earned a reputation for undertaking clean and elegant experiments with penetrating discussion. At Wits, an informal grouping comprising Dave Holt, Paul Jackson, Dave Allinson, Rob Caveney, Jim Murphy and Ewald Wessels was formed to promote electron microscopy. A consequence of Matthews? frequent visits to Charlottesville resulted in increasingly close collaboration with the IBM Watson Research Center. In 1969 he left Wits to take up a position at IBM as manager of a research group heading their thin film research. Matthews’ contributions to the field of electron microscopy are recognized through the annual John Matthews Memorial Lectures which are given at the meetings of the then Electron now Microscopy Society of Southern Africa (MSSA). Recently, as part of a major revamp and modernization of the Unit, a number of new microscopes have been purchased, including a focused ion beam scanning electron microscope (FIB) and two atomic force microscopes (AFM).

M-auer Spectroscopy. This activity was started by Berend Kolk, when he was appointed to the Chair of Experimental Physics at Wits in 1983. At the time two other groups in the country were doing very limited M-auer work. Kolk had been schooled in the technique at the University of Groningen. After obtaining his doctorate he did post-doctoral work at Rutgers University and then moved to Boston University where he was based for seven years. On arriving at Wits, Kolk immediately set about establishing a foremost M?auer laboratory and also vigorously promoted benefits of the technique to colleagues in industry and academia around the country. Already in the early stages of the laboratory, both high-temperature and low-temperature (cryogenic) capabilities were implemented. Fundamental physics projects that were tackled included magnetic behavior and spin dynamics in the vicinity of the spin-ordering temperature of Fe-metal, and lattice dynamics aspects of superconductivity in the ‘high-Tc’ superconductors of the time, namely the so-called A15 compounds, Nb₃Sn , V₃Sn etc. Those fundamental physics projects formed the core of the research programme in the laboratory.

In 1987 Kolk tragically passed away, and the responsibilities of the M-auer laboratory fell to the most senior student, Giovanni Hearne. About two years later, Herman Pollak was recruited to take over the running of the laboratory. His research emphasis and interests were somewhat different to that of Kolk, being more inclined toward applied and industrial physics project work. This found many applications in the country especially in areas of mineral processing, metallurgy and catalysis. In the course of the next several years Pollak established many linkages with industry, helping to cement the place of M-auer spectroscopy as an important analytical tool for iron-bearing materials in the country. After a sabbatical in Israel, Hearne returned to the Department of Physics at Wits in 1995. He continued to assist in guiding activities in the M-auer Laboratory as well as establish a new high-pressure research programme based on the knowledge gained during his tenure as a post-doctoral fellow. He is currently group leader of the M-auer Laboratory.

Mechanical Properties of Materials. In spite of Nabarro being a theoretician, most of the students he supervised and researchers he interacted with at Wits were experimentalists. Paul Jackson was the first of the students, and worked on the mechanical properties of metal whiskers. D. B. Holt, a member of the Department in the 1960s was co-author with Nabarro and Basinski of an extensive review on the plasticity of pure single crystals. C A O Henning obtained his PhD in 1967, supervised by Ludwig Schog, and on the growth of gold films on rocksalt in high vacuum. R J (Rob) Caveney obtained his MSc and later a PhD on the vapour growth of CdS crystal platelets.

Research on fracture developed into a substantial activity from 1956 on, through the establishment of the Drilling Research Unit with support from Board and Hardmetal. R M Ferguson of Boart had suggested that attention should be paid to improving the performance of rock drills by using ‘rock hardness reducers’, which lower the energy of the drilling by reducing the stress at which the rock fractures. E T S (Ted) Brown then approached Nabarro suggesting further investigations into this effect, both in the laboratory and the field. To start with, this was mainly carried out by Helmut Schlon and Ludwig Schog. Somewhat later Charlie Levitt obtained his PhD on the impact strength of diamond under different rates of strain, by mounting diamonds in a massive pendulum and smashing them against each other. Tony Ball was a member of the Department between 1969 and 1972, working on the fracture of quartz crystals and quartzite

From the early 1960s Boart became interested in the fracture of hardmetal rock drilling tools, and the Drilling Research Unit launched investigations into mining insert design, internal stress measurements of tungsten carbide, residual stress measurements of braised joints, and the influence of heat treatment on hard metal properties. Much of the drive was to be provided by Silvana Luyckx. In the early 1970s interest shifted from fracture of WC-Co to its magnetic properties. These were exploited in a number of quality control techniques, but were not really understood. Irwin Joffe started work in this field, and his discovery of the role of Co₃W microprecipitates is still often quoted today, and used worldwide as a quality control technique. In the mid-1970s McLachlan built an uniquely large magnetometer for Boart and Hardmetal in Springs, and the effect of inclusions on the strength of hardmetal was studied and quantified. In the 1980s Boart’s interest focused on the effects of ion implantation, and Luyckx moved the base of her activities to the Schonland Centre.

Biomaterials. Interest in biomaterials in the Physics Department has mainly centered on Nabarro and a number of associates. One of his early biomaterials interests, partly stimulated by Bill Harris and Sheila Saffer, was in the application of the ideas of dislocations and disclinations to biological materials. This led to an analysis of the structure of an insect muscle, which appears to have anticipated the ideas of some biologists and, during a sabbatical in Berkeley in 1977, to a successful mechanistic description of the crenation of red blood cells by drugs. With Roger McCarter and C H Wyndham, he published on the reversibility of the length tension relationship in muscle. In the 1970s there was a research program involving the study of the mechanical strength of Insect shells, the principal investigators being Irwin Joffe in the Physics Department and H R (Randy) Hepburn in the Department of Physiology. In the last months of his life Nabarro motivated for the support of biomaterials research, and chaired a meeting that brought together interested parties in Gauteng to discuss the desirability of establishing a centre of excellence in biomaterials. The outcome was extremely positive, and led to a National Conference on Biomaterials in September 2006.

Condensed Matter – Theory. Frank Nabarro, achieved world renown for his pioneering contributions to the theory of crystal lattice dislocations and their role in the plastic deformation of solids. He wielded enormous influence on materials science through his monograph ‘Theory of Crystal Dislocations’, published in 1967 the encyclopaedic series of books ‘Dislocations in Solids’ which he edited. In later years he turned his attention to quasi-crystals, dislocation patterning, and creep resistant materials and rafting in superalloys, which with H L de Villiers he surveyed in the monograph ‘The Physics of Creep’. Over the years he wrote a number of papers expanding on the concept of the Peierls-Nabarro stress. He never stopped being active in research, and in the last year of his life brought out two papers.

The beginning of a sustained activity in computational materials modeling was the arrival of J E (Ted) Lowther at Wits in 1972, and was further strengthened when Daniel P Joubert joined the Department in the early 1990s. Much of Lowther?s early research was on deep levels in semiconductors. In the 1990s his interests moved towards impurity centres in diamond. Since the late 1990s his main efforts have been oriented towards calculating the high pressure phases of carbonitrides and other materials that could potentially rival diamond in strength, and this has become a focus area under his management in the CoE in Strong Materials. Joubert’s research has mainly been of a more fundamental nature, developing the concepts and mathematical tools of density functional theory for application to the calculation of electron states in solids.

Richard E Nettleton, joined the Department in the early 1970s, and embarked on research in statistical mechanics and thermodynamics. Prior to 1984, he investigated a number problems, including phase transitions in random magnetic lattices, especially branching structures, Landau Fermi liquid theory of normal ₃He, lattice dynamics and phase transitions in ferroelectric crystals, on which Yehuda Tuval obtained his PhD, and percolation and frustration in spin glasses and the XY model, which he worked on with Michael J Stephen. After 1984 he seems to have worked exclusively in the field of extended non-equilibrium thermodynamics. He had a postdoc, E S Freidkin, working with him, and in 1995 he published a review and a couple of other articles on the subject with S L Sobolev, but mostly his output was in the form of sole authored papers. He retired in 1995, but remained research active, and passed away in 2007.

Arthur Every joined the Department of his alma mater in 1970. His main line of research is the theory and computer modeling of elastic wave propagation and phonon transport in elastically anisotropic solids. The phenomena he has treated include the phonon focusing patterns of crystals, waves in fluid-loaded solids, and their study with acoustic microscopy, internal diffraction in crystals, boundary limited thermal conduction, surface Brillouin scattering, and laser generated ultrasound and elastodynamic Green?s. Most recently he has been working on the effects of spatial dispersion. His broad interest in elastodynamics has found expression in the book, coauthored with A.K. McCurdy, Second and Higher Order Elastic Constants of Crystals, Vol. 29a in the Landolt Btein series, and in the co-editing with W. Sachse, of Vol. I of the Handbook of the Elastic Properties of Solids, Liquids, and Gases, published by Plenum. He retired at the end of 2006, but remains attached to the Department as an Emeritus Professor.

Interestingly, two of the research associates of J H N Loubser have written books on symmetry and group theory in physics. David Schonland, son of Basil Schonland, spent his 1964-5 sabbatical year from Southampton University in Loubser’s group. There he put the finishing touches to his book ‘Molecular Symmetry’, which was published by Van Nostrand in 1965. Tony Wolbarst was taken on as a postdoctoral fellow by Loubser some years later, and wrote ‘Symmetry and Quantum Systems’, which was published by Van Nostrand Reinhold in 1977.

The Schonland Research Institute for Nuclear Sciences

Originally springing from the Physics Department in 1958 as the Nuclear Physics Research Unit, under the Directorship of Sellschop, the Schonland Research Centre soon took on a character of its own. Although some of the earliest research was concerned with cosmic-ray particles having the highest energies obtainable on Earth, the Schonland came to specialize in relatively low energy pure and applied nuclear research, particularly applications of nuclear analytical methods to minerals, materials and the environment. The Schonland was declared a Centre of Excellence of the Foundation for Research Development in 1984. In accordance with the 1996 Schonland Umbrella proposals, it was restructured as a federation of four Research Programmes, each with its own group leader, sharing common support infrastructure. The Health Physics Service was also housed at the Schonland. Recognition by the University as a Research Institute came in 2000. There was collaboration with the Physics Department in undergraduate teaching, and with that or other Departments in certain research areas. Postgraduate students were involved in all the Schonland research programmess, and the output of higher degrees was about three per year. Suitable short projects for the undergraduate student curriculum were also integrated into the research undertaken. A new era dawned in January 2005, when the facilities of the Schonland Institute were transferred to the NRF, and it became the Northern Branch of iThemba Labs. Much of the dynamism of the Schonland Centre can be attributed to Sellschop, who over the years received a number of honorary doctorates and other awards.

Left: Mike Olivier and Don Mingay in front of the Cockcroft-Walton accelerator around 1963. Right: Friedel Sellschop in his birthplace Litz for an international conference in his honour in 2000.

At the Handover Ceremony in December 2004, Balt Verhagen has this to say on the early days at the Schonland (slightly amended):

‘I happened to land up at Wits after having been effectively booted out of the University of Pretoria. I had been working towards a PhD and Nabarro kindly gave me a home in the Department of Physics. There I took over a project of Marisa de Leonardis Mellini. It concerned the isotopic enrichment of tritium, which has hydrological significance. Anglo American, with their water problems in deep gold mines, was interested and was providing some finance.

Just at that time, the Nuclear Physics Research Unit of the Department of Physics was being established with Friedel Sellschop, who was working towards his PhD in Cambridge, as its first director. The tritium project fitted in with the aims of the Unit and thus it became its first activity and I its first employee. This is historically significant: the NPRU -later the Schonland Research Centre, later still Institute – from its very inception had environmental physics as one of its major concerns and thus developed a multidisciplinary tradition.

The former mining and military hospital at Cottesloe had been donated to the University to act as a residence for World War II veteran students. It was into these barracks that NPRU originally moved. It was rather primitive: services had to be laid on, offices, a workshop and library were established. Sellschop returned to Cambridge for 6 months to complete his PhD. Adrienne de Villiers, and John Nelson joined. Div Kerr was appointed as the first University isotope officer. Machine tools for the workshop run by Libero Verga were bought from Pop Leibengut, a fine instrument maker recently retired. Geoff Miller ran the electronics.

I began on the design and construction of a two-stage thermal diffusion enrichment column under the unit s first of several IAEA contracts. Div Kerr skillfully built and commissioned a cobalt-60 irradiation unit which, apart from its research applications, in the following decades produced sterilized bone for scores of transplants. Don Mingay joined, having done his PhD at Harwell. Altogether, the pace of development became quite intense. All these activities could be financed. A modern accelerator had altogether more serious budgetary implications. The Cavendish laboratory was scrapping their 1930’s Cockcroft-Walton accelerators. The components of one were shipped to Wits, the bits of another went to Potchefstroom University. Voltage doubler stages were assembled by a young Australian visitor Des Laurence. The University allocated some unused land on the very north end of Campus, on Empire Road and here the first accelerator building was constructed – the Tin Temple .

Wynand Mouton, then working towards his PhD in Utrecht joined the staff but was frustrated that there was no working accelerator facility. During one of Friedel s absences abroad, Wynand took another Australian, Marsden to visit the DeBeers Diamond Research Laboratory and there came face to face with a small electron accelerator which had been acquired some years before for irradiating diamonds. Wynand, working on nuclear spectroscopy, immediately saw its potential, and with Mike King and other students ran the first nuclear physics experiments at the Unit, using bremsstrahlung gammas, varying the energy using the Compton effect. The historic Cambridge machine was eventually brought into operation, appropriately called Phoenix , and inaugurated in 1960. For many years it was successfully, if labour-intensively, used for a variety of experiments. Rex Keddy, with his medical physics background, joined the staff and became Deputy Director. In December 1964 the Unit finally moved into its present building on campus, which was linked to the pre-existing Tin Temple and the cobalt-60 vault.

The Diamond Research Laboratory donated its small electron accelerator to the Unit. Although the manufacturers had assured its original owners that this was impossible, the pressurised Cockcroft Walton machine was skillfully and successfully rebuilt by Don Mingay, Laurie Hoare, Mike Stemmet and others to accelerate positive ions. It replaced the cumbersome Phoenix, which many years later was dismantled and resurrected as an exhibit in the Museum of Science in London, where it can be viewed to this day.

The Environmental Isotope Group successfully transplanted the thermal diffusion equipment into a special shaft of the new building. In addition. low-level counting equipment was home-built, the first environmental tritium and radiocarbon measurements in South Africa were performed and active isotope hydrology commenced, again under IAEA contract.

John Watterson, Carl Erasmus and Hugo Andeweg were seconded from the National Institute for Metallurgy to the Unit and started a neutron activation group. This group eventually developed and successfully operated a unique instrumental analytical facility which did pioneering mineral work on e.g. the geochemistry of the Bushveld Complex.

All this time the Director, Friedel Sellschop had been furiously busy. Amongst many other initiatives, he had arranged for the first experiment to detect neutrinos in nature to be conducted using South Africa s deep mining environment. The Case Institute for Technology sent scientists to install a 2 mile deep laboratory in the ERPM mine in the East Rand. Neutrinos were indeed detected in this impressive cooperation involving Wits staff and students.

The 1960s and 1970s saw the global proliferation of tandem accelerators. These relatively compact machines pioneered the understanding of low-energy heavy-ion physics at just above the Coulomb barrier. Through the determined efforts of Sellschop, an EN Tandem van der Graaff accelerator reaching 6 MV was obtained from High Voltage Engineering Corporation, and installed in a purpose-designed building in 1973. Its purchase was quite a saga. The order had already been placed when it transpired that the external support and necessary authority for the payment had not been obtained. An attempt was made to cancel the order, but the contractual cancellation fee was so high that the purchase was ultimately allowed to go through.

An ambitious set of experimental beam lines was installed for a variety of experiments in nuclear structure physics, leading to the first PhD, for John Carter, in 1978. Pioneering work on channeling and dechannelling in diamond was performed by Trevor Derry and Roger Fearick. Later experimentation in nuclear scattering produced MScs for Bridget Caragher, Elias Sideras Haddad and Zeblon Vilakazi and PhD for Erich Muskat. Throughout all these endeavours, an important contribution was made by Vladimir Hnizdo, a member of the Department. Running and developing the tandem facility proved to be costly, and funds constantly had to be diverted from other Unit activities for this purpose. An early intention was to run accelerator mass spectrometry. Positive steps to build up the necessary detector and ion source facilities were taken only fairly recently in the latter 1990?s by Simon Connell and others, as was the partial automation of the accelerator control system by Hugo Andeweg. By that time, various components of the high voltage generator and accelerator column had deteriorated with age, requiring refurbishment beyond the very pared-down budget at that stage.

In the seventies diamond physics became a prominent research theme at the Unit, pioneered under the late Haro Fesq to be followed by Trevor Derry, Carl Erasmus and with Miklos Rebak perfecting techniques of preparing diamonds for a variety of experiments an applications. Through a life-long friendship with Henry Dyer of De Beers, Sellschop had unique access to diamond samples, and these were his passport to many international collaborations.

The Environmental Isotope Group became increasingly involved and recognized in the field of isotope hydrology, in particular in the Kalahari, being given one of the first major research contracts by the newly-established Water Research Commission in the middle 70s.

Harold Annegarn started an aerosol research group using PIXE – proton-induced x-ray emission – as the main analytical tool for the elemental analysis of dust samples collected from air. A proton microprobe was constructed and placed on one of the tandem beam lines.

Under pressure from the then VC Sonny du Plessis, Sellschop resigned as Director to become DVC Research. The Centre briefly continued under Rex Keddy as Acting Director. During this period, the University of Potchefstroom donated its small van de Graaff machine, bringing to four the number particle accelerators at Schonland. Later, the University moved to close down many of the Centre’s activities, claiming major budgetary shortfalls. After painstaking investigations by the newly-formed governing committee, it was shown that the Centre’s finances were in fact quite healthy. The staff complement had shrunk to about one third of what it had been in the mid-eighties and cost recovery measures could balance the books. The Environmental Isotope Group had managed to become largely self-funding and the Aerosol/Atmospheric Physics Group even set up an independent business unit.

In spite of this, continued attempts were made to rationalize the Centre, which time and again were countered by a spirited defense of the governing committee. A new operating model, the brainchild mainly of John Watterson, as a collection of facilities run by the Environmental Physics, Nuclear Physics, Materials Science and Accelerator Research Groups was finally approved by the university, and the Centre re-named an Institute. Such a multi-disciplinary facility, with a strong environmental emphasis, might well have acted as a model for organizing other university research endeavors.

The nineties were a period of success for the Applied and Environmental Physics Programme. A major thrust towards diamond ore sorting using intense neutron beams obtained substantial funding from DeBeers, producing interesting work on neutron imaging. The Environmental Isotope Group landed numerous research contracts, its leader was often engaged as consultant and in late 1999 the laboratory received a major upgrade of its ageing and home-built equipment with automated analytical instrumentation to act as regional centre for an IAEA Southern and Eastern Africa isotope hydrology project.

In 2003, the university announced that it would be withdrawing the minimal financial support it had been giving the Institute at the end of 2004. The main cost centre was of course the tandem accelerator, as it had been from the time of its installation. The Institute is continuing as a part of iThemba LABS (North) and will be funded by the NRF.?

Some notable achievements and ‘firsts’ for the Schonland Centre were:

Detection of the first cosmic ray neutrino ever seen (February 23 1965) by Reines, Sellschop et al, in an experiment set up underground by a collaboration of the Case Institute of Technology, Wits, and the University of California at Irvine.
Trace element analyses in diamond, mostly by neutron activation analysis, show a definite chemical signature of the Earth?s upper mantle; other experiments establish boron as the electron acceptor in natural semiconducting diamond (1977).
Synthetic doping of diamond as a semiconductor achieved for the first time using ion implantation and ?defect engineering?; the use of diamond dosimeters for radiotherapy established and patented; nuclear hyperfine techniques applied to foreign atoms implanted into diamond give information about the lattice sites (1988).
Environmental studies of dust pollution in the air using proton induced X-ray emission analysis reveal a large and unexpected source of the dust in gold mines (1988).
We make an early contribution to the search for a new neutral subatomic particle, in a publication which has been widely quoted internationally (1988).
The use of tritium, ¹⁴C and stable isotopes in the environment to monitor underground water resources, establishes the existence of recharge in the Kalahari Basin (published 1990).
Platinum group metal analyses by charged particle activation, together with light isotope ratios, in samples from a South African Cretacious/Tertiary boundary, contradict popular ideas on the extinction of the dinosaurs based on northern hemisphere measurements (1990).
An international survey shows that our output of refereed publications on diamond over the last six years was second highest in the world (1992).
Work on unraveling the formation of the early continents, with the aid of nuclear analyses, makes the cover-story of ?Nature? (1992).
Diamondiferous and barren kimberlite ores distinguished for the first time by a (nuclear) analytical method, with strong economic implications for the diamond mines (1993).
Our world-class diamond preparation facilities support a collaboration with scientists at the European Synchrotron Radiation Facility, to develop diamond crystal monochromators for their powerful X-ray beams (1995 ? present).
Regional courses on Radiation Protection for the whole of Africa commence under the auspices of the International Atomic Energy Agency; the Environmental Isotope Laboratory supported as a Regional Centre for the study of groundwater etc. by the IAEA (1999).
A new radiometric method for sorting diamonds developed for industry (~2000).
A longstanding ?pure nuclear physics? programme studying the calcium nucleus, with Cape and German collaborators, publishes their results in Physical Review papers (2001).
Dosimetry studies for breast cancer diagnosis by mammography, using diamond detectors, attract considerable support from the medical profession (2001-).
Continuing investigations of the atoms terminating polished diamond surfaces, show that the outermost atoms are modern carbon bonded from the polishing oil (2003).

High Energy and Nuclear Theory

Theoretical Physics as distinct from Solid State Theory was initiated at Wits with the establishment of a Chair of Theoretical Physics and the appointment of Christian Toepffer to that position in 1973. A further strengthening of theoretical activities was achieved with the appointment of Richard H Lemmer to the new Chair of Mathematical Physics in 1977. Subsequent appointments at the Senior Lecturer level were taken up by the active researchers Barry J Cole and George Delic. When Toepffer left, he was succeeded by W Dieter Heiss in 1982 who had been Head of a Division at the National Research Institute of Mathematical Sciences of the CSIR. When Heiss took over, he could build on the well established structures of research activities including seminars, undergraduate and postgraduate teaching in subjects of theoretical physics and, of course, ongoing research focusing on nuclear and hadronic physics. The group was joined in 1985 by Jo?A P Rodrigues, who expanded the existing activities by his major subject, field theory with special focus on string theory. Among the students supervised by Rodrigues, Robert de Mello Koch joined the Centre in 1999 after completing a post doctoral year at Brown University, and Phil Ferrer, then completing his PhD, joined the Centre in 1998.

The years following have seen a very active group with a regular weekly seminar series, a well established teaching program enjoying the support of the whole Department such as a full two semester course in Quantum Mechanics for Third Years (then a novelty in South Africa) followed by courses in advanced topics (Many Body Theory, Scattering) for the Honours. The research activities exposed and discussed in the seminars attracted an appreciable number of some of the best students thereby further enhancing the research output. The success was noticed by the new Professor in Applied Mathematics, Peter GL Leach, whose interest centred on Nonlinear Differential equations and Lie groups, a subject of interest in particular to Dieter Heiss with his activities in Chaos and Quantum Chaos, but also to George Delic for Computational Physics. A Centre for Nonlinear Studies was created in 1987 comprising about 15 active researchers of both Departments, Physics and Applied Mathematics. Because of divergent research interests, Richard Lemmer did not join the Centre. The seminar series of the CNLS, now jointly organized, gave rise to substantial cross fertilization in physical and mathematical problems and had from there its essential positive impact. When the major driving force for the joint venture, Peter Leach, left for Durban, the Centre lost its appeal to most of its participants in Applied Mathematics.

The Centre of Theoretical Physics continued its activities as from 2000 with a considerably reduced participation from Applied Mathematics but still a strong and active participation in theoretical physics. The research activities continued to be Nuclear and Particle Physics and String Theory; one particular line of research was followed by Dieter Heiss and his research students: Exceptional Points being singularities of spectra and eigenfunctions, they play a role in quantum phase transitions and quantum chaos, their individual existence has been shown to be a physical reality in experiments initiated by Dieter Heiss. In the early 1990s Rodrigues, working with collaborators from Brown, wrote down the first non-perturbative string field theory relevant for the description of the c=1 string. More recently, de Mello Koch and Rodrigues gave some of the first studies of instabilities of bosonic open string theories which is described by the mechanism of tachyon condensation. Since 2002 non-perurbative quantum gravity has been explored by employing the gauge theory/gravity correspondence. A further broadening of activities came with Fabio Frescura who joined the Department in 2000. The activities of the theory group impacted upon the Department as a whole, not only in the teaching and seminars but also in frequent research contacts, in cases leading to joint publications. Dieter Heiss left the Department when he accepted an offer by the University of Stellenbosch in 2002, and Rodrigues was appointed Director of the Centre.

The Nuclear and Particle Theory Programme was established in 1987 under the directorship of R H Lemmer. It was later upgraded to a group when Rudolph Tegen joined. The activities of this group centred, at least to start with, around theoretical aspects of quark physics and heavy ion physics. Lemmer retired in 1997 and Tegen resigned a few years later.

Medical Physics

The Medical Physics Division was established in 1956 under the aegis of Phil L P de Valence. While it has been based at the Johannesburg General Hospital, a close association with the School of Physics at Wits has always been maintained, and a medical physics option has been available in the Physics Honours course. All Medical Physicists have at least an Honours degree in Physics or Medical Physics. The Wits department has always had an active academic and internship training program, being one of 6 departments in the country that are accredited to train. A fulltime MSc program by coursework and research report was started in 2003. Since 1994, there has also been an active International training program and at least 10 fellowships have been awarded to Africans to receive training in the Division. Following de Valence?s departure in 1976, the succession of Heads has been J C Botha, R Moore, M J Scott, and R J Keddy and Debbie van der Merwe, the present Head.

Astrophysics

The earliest record of interest in astronomy or astrophysics at Wits is a paper on the galactic system read to the Scientific Discussion Society by M Krook in 1932. Somewhat later Arthur Bleksley in the Department of Applied Mathematics emerged in the public eye as a leading astronomer and spokesman for science in South Africa. In the late 1960?s William Ramsey was appointed to the Physics Department. He had worked in the Niels Bohr Institute in Copenhagen, and came with high recommendations from Bohr. For many years David Bloch, who is based in the School of Applied Mathematics, has been the most notable astronomer at Wits. In the School of Physics, our present involvement with astrophysics is mainly through the activities of Fabio Frescura, which began in 2001 when he was asked to do some modeling of precession by HartRAO. He has served on the SAIP Astrophysics and Space Science Specialist Group and other committees. Links with HartRAO go back quite a few years. George Nicolson supervised at least one student, and Derck Smits presented an honours topic in the Department for several years. Claire Flanagan single handedly set up and ran the HartRAO pulsar monitoring programme until she became director of the Johannesburg Planetarium.

Physics Education

In 1970 the government decided that the training of high school science teachers should be removed from the colleges, and be placed under the control of universities. As its first physics methodologist, the Wits Physics Department in 1971 appointed Peter Hewson. Although initially a theoretical physicist, Hewson had transferred his research interests into Science Education, and his papers on conceptual change strategies remain extensively cited in the literature. At about this time the university also appointed Professor J W Brommert, author of the textbook Physics for South African Schools to act as Dean of Education. Regrettably his books, although keenly taken up by the private schools, who often teach physics and chemistry as separate disciplines, made no impact on the government education departments. They insist on teaching physics and chemistry as an integrated discipline, physical science, with textbooks written specifically for this combined syllabus. In 1982 Mike Stanton joined the department as a ?backup? for Hewson (who resigned and relocated to Cornell in 1984). His interests have been in alternative conceptions in electric circuits, and the history and philosophy of physics. In the next two decades there was considerable expansion in science/physics education. A notable departmental member involved in physics education during this period was Margaret Rutherford, later to be Principal of the College of Science, whose area of expertise lay in the role of language as a determinant in the acquisition of science concepts. One of her students, Doug Clerk, joined the Physics Department and carries on her work in the language in science.

Teaching, Graduate Studies and Outreach

For long, undergraduate teaching has divided into the major stream, which terminated at the Honours level, and auxiliary or service courses for students majoring in other branches of science or studying in other Faculties, particularly Engineering and Medicine. As government racial restrictions on the intake of students started breaking down in the late 1980s, the Physics Department was confronted by increasing numbers of ill-prepared students, and a number of intercessions were implemented, such as slow stream courses and other forms of academic support. These were consolidated with the launch of the College of Science.

The numbers of postgraduate students declined dramatically in the 1970s with years in which none registered for higher degrees. In the 1980?s the numbers increased, and reached a steady state of between 40 and 50 students registered in any given year. This was helped by the launch of the FRD (later the NRF) research funding programme that provided studentship support to grant-holders. When the Faculty rules were changed to permit MSc degrees by coursework and research report, advanced lecture courses in physics were introduced. Some of the lectures were given by outside persons from institutions such as the CSIR and HartRAO.

The PG Dip Sci Radiation Protection and Safety of Radiation Sources , was established in 1998 as a joint collaboration between the School of Physics and the IAEA. The initial driving came from Professor J I W Watterson (Wits) and Phil Metcalf (Council for Nuclear Safety), with much technical input from Prof Tom Nam of the Health Physics Unit at Wits. The course has been run collaboratively since June 1999. In 2000 the PG Dip Sci in Physics, Engineering and Safety of Nuclear Power Reactors was created at Wits. In 2005 this course was re-established at Koeberg, where it has become a joint University effort with teaching input from the Universities of Stellenbosch, Western Cape and Cape Town.

Outreach to the community, publicizing physics, has been an integral component of the Physics Department?s activities from early days. The brochure for the Commemoration Day of 1926 lists the physics demonstrations that were put on. In the 1980?s Peter Ford and Tony Voorvelt were the champions of raising public awareness of Physics, organizing physics fun days and other activities, and both became well known for their spectacular demonstrations. A big impetus for public awareness was the Diamond Jubilee of Wits in 1982, which was celebrated with an ?Open Week?, which was visited by approximately 2000 people during the five days.

Political Ferment at Wits and in the Physics Department

The post Second World War period up to the arrival of democracy in 1994, was a time of intense political ferment at Wits, and this impacted on the Physics Department in various ways. Tensions came to a head after the passage of the separate universities act in 1959 and the sabotage campaign that followed it in the early 1960?s. Two members of the Physics Department, Baruch Hirson and Lionel Gay, were caught up in this campaign, and Hirson was incarcerated.

In practice, the University had to abide by the laws of the land, which for many years restricted the intake of blacks into undergraduate courses. Exemptions in limited numbers were made for students wanting to do a course which did not exist at a ?Homeland University?, and a few got in that way. During the earlier years of the closed period, black postgraduates were supervised at Wits but had to be registered at UNISA or elsewhere. In time this restriction too was relaxed. Since then a steadily increasing number of blacks have been graduating with higher degrees (and also bachelors and Honours degrees) from Wits.

The restrictions on the recruitment of blacks onto the academic staff, were also in time gradually relaxed. The first black lecturer in the Department was Chris Madiba, who was appointed around 1980. Since then the ethnic diversity of the Department has steadily increased.

Distinguished Alumni

The first graduates of the department that achieved distinction did so outside of the field of physics ? B A Ettlinger (1919) was an Acting Judge of the Supreme Court in 1947-48, C. J. Cl sen (1923) was Judge President of the High Court of South West Africa, H J N Nethersole (1924) was managing director of the English Elelctric Co of South Africa, J E Kerrich (1925) professor of statistics at Wits. In 1925 there was C N Jackson, an astronomer, while H J Logie (1938) became our first home bred professor of physics.

Ex students who have since made their name in physics include S Mandelstam in nuclear theory, P T Wedepohl in diamond physics, C G Kuper in superconductivity, J W Matthews in crystal epitaxy, E Leader in theoretical physics, D G Pettifor, FRS in computational materials modeling, A C Readhead in astrophysics, J B Hutchings in astronomy, S Teukolsky in theory of gravity and coauthoring the book ?Numerical Recipes? and R H Dauskardt in materials science. A number of Wits graduates have become professors of physics, or other fields, including J D Comins, T Derry, A G Every, F Frescura, D Mitchell, P E Ngoepe, M Orkin, J Rodrigues, C Simkins, A Strydom, D van der Merwe and R McCarter. A number of Wits graduates have achieved high office in government and science management, including P Mjwara (NLC, DST), C C P Madiba (DNE), R Caveney (DRL, Wits Enterprise) and M Fish (ElementSix).

University of the Witwatersrand Physics Department Contact