David Clark's Research Group

[Dr David Thomas Clark was appointed from October 1964 to a lectureship in chemistry at Durham. The lectureship was held dormant while he occupied a twelve-month Fulbright Fellowship at the California Institute of Technology (USA). From the lectureship in 1965 he became successively reader (1972) and professor (1979), while his interest in physical organic chemistry and computational modelling spread to the study of the surface chemistry of polymers and other organic compounds by X-ray photoelectron spectroscopy. He chaired the Board of Studies in Chemistry from 1 June 1981 until 30 June 1983 (the first four months as acting chairman) Head of Department; two months later he left the University to become director of Imperial Chemical Industries' New Science Group at its research centre in Wilton. In retirement he lives in Durham.]

Group members, by year of joining (on October 1 unless stated) (Each postgraduate listed obtained the qualification shown.)

1966 Graham Smale Ph.D. (i.e. started a Ph.D. study period of 36 months full-time); 1969 David Kilcast (postdoctoral, to 1971, Sep.), David J. Fairweather and David M.J. Lilley Ph.D.s; 1970 David B. Adams and David Briggs [D.Sc. 1986] Ph.D.s; 1971 Ian Lochy (postdoctoral, to 1972); Ian Scanlan Ph.D.; 1972 Herbert F. Beer M.Sc. (i.e. started an M.Sc. study period of 12 months full-time); 1973 David B. Adams (associated senior demonstrator, 36 months), Ian Sadler (postdoctoral, to 1974), Jiri Müller Ph.D.; 1974 Herbert F. Beer and Alan Dilks and Ian Scanlan Ph.D.s, H. Ronald Thomas M.Sc.; 1975 Thomas Fok (postdoctoral, to 1977, Dec), 1977 Alan Dilks (postdoctoral, to 1978), Benjamin J. Cromarty and Derek Shuttleworth and H. Ronald Thomas Ph.D.s; 1978 M. Zaki Abrahman and Alan Harrison and Peter J. Stephenson Ph.D.s; 1979 W. James Peeling (visiting postdoctoral, CDN/Manitoba, to 1981), Hugh S. Munro Ph.D., Rosemary Wilson M.Sc. part-time (i.e. started an M.Sc. study period of 24 months half-time); 1980 Mohammad M. Abu-Shbak and William J. Brennan and Umar Hayat and D. Richard Hutton Ph.D.s; 1981 Graham Beamson (associated senior demonstrator, 23 months), Andrew H.K. Fowler and Stephen (Arthur) Johnson and Rosemary Wilson Ph.D.s (final 12 months of full-time study supervised by Hugh Munro); 1982 Lynn Colling (postdoctoral, to 1983).

David Clark, contributing in August 2012, writes as follows about his research group at Durham. (His memories that are more general are at The 60's and The 70's.)

Our workspace

Initially, research students in the group were located in the main chemistry building either sharing first-floor laboratory space with the crystallography research group (rooms 120J and 120K in 2012) or in the ground-floor fluorine research laboratory (room 27). With the end of radiochemistry research in 1969, the Clark group acquired the western of the two linked huts that had housed the Londonderry laboratories (on the site of the piazza between the Dawson Building and the Calman Learning Centre), the other being taken over by the mass-spectrometry service.

The hut provided excellent space for the research group, fostering a relaxed yet hard-working research environment where the research students and postdocs had unrivalled flexibility to customise the space. Miraculously, settees and easy chairs appeared from the sale rooms where Dunelm House now stands, forming the core of a home-made coffee lounge, with a blackboard and even a dart board to facilitate relaxed research debates and discussions. It was rumoured, probably apocryphally, that the group had considerable expertise in home brewing and that some members were semi-professional dart players for the Vic's team in Hallgarth Street, which competed in the regional league. This was an era before health and safety legislation had borne down on universities and in consequence group members often worked through the night. An enormous amount of research ensued, with each postgraduate contributing to many papers and completing Ph.D. studies in well under three years.

The growth of the group's need for space was matched by growth in the research needs of other science departments. In 1976 the Clark group and the mass-spectrometry service had to vacate the Londonderry huts and move to the ground floor of the west wing of the main building, taking over what had been the laboratory used to teach 2H physical chemistry (in 2012, rooms 1 and 1X). This space was larger and better serviced but lacked the flexibility and informality of the old lab and its home-made coffee room. To preserve the group atmosphere for the rest of my time in Durham, regular evenings for wine, cheese and competitive games were hosted by the Clark household, with tournaments in the large games room offering snooker, pool, darts and table tennis.

Our visiting researchers

Until 1986, the Department did not record visits, athough some were reported by hosts to the University Senate to satisfy formalities overseas. Longstanding academic collaborations that required significant two-way visits included links with Professor Antonio Sgamellotti, who visited for 6 weeks every year from 1972-78 to work on core ionisation theory, and Professor Francesco Tarantelli, who made similar visits in the period to about 1980. They came from the University of Perugia and stayed at Van Mildert College during their visits. Indeed Antonio became so popular in the College senior common room that he was called upon to give artistic advice on the redesign of the SCR facilities. Professor Harald Fritzer from the University of Graz often visited for mutual XPS studies of unstable transition-metal azides. A particularly exciting time was had by all when one of his samples exploded in the XPS spectrometer. Fortunately the only damage was to an X-ray window, easily repaired. A longstanding collaboration with Professor Antonino Recca in the area of polymer surfaces and synthesis was strengthened through his spending a sabbatical year in Durham in 1983 on leave from the University of Catania.

Our research

As a consultant to AEI Scientific Apparatus (later Kratos), I was involved at an ealy stage in the design of the first commercial X-ray photoelectron (XPS) spectrometer, the ES100, capable of variable take-off-angle studies. With funding provided by SRC (the Government's Science Research Council, superseded in 1981 by SERC; since 1994, engineers and physical scientists have dealt with EPSRC), my research group took delivery in 1969 of the first commercial ES100 to be made. It was superseded by the ES200, with a monochromatised Al K-alpha X-ray source and more advanced sample handling for organic and polymeric materials. We needed greater non-destructive depth resolution so we designed Ti K-alpha X-ray sources. An anode of novel design, machined from monolithic titanium, was produced in the Science Site Workshop; precision machining of the metal was notoriously difficult at that time, so the metalworking was quite a feat. The anode led to the first systematic use of a harder X-ray source (energy 4.5 keV). [The close links with Kratos in the design of XPS spectrometers and associated sample handling produced a novel design for studying nitrogen-14 NQR spectra, which was also of interest to Professor Waddington’s group.]

To complement the experimental work, I set up a team to undertake ab initio quantum mechanical studies of photoionisation phenomena. This required high-powered computing facilities intially available only from the Atlas Computer Laboratory (1961-75) at Chilton, so when the Northumbrian universities' multiple-access computer committee was set up, around 1967, I became a founder member. NUMAC was one of the few joint Durham-Newcastle University committees, controlling the development of the jointly owned IBM-based multiple-access computer (commissioned in 1967) and access to it. It was one of the most advanced available at that time in any UK university. John Major and Mike Scarrott (Physics Department) needed it for bubble-chamber analysis so we formed a Durham contingent and negotiated unique access to the main frame at weekends. This involved a number of shifts running the computer on a one-to-one basis. In consequence the Clark group completed many ab initio quantum-mechanical studies of core-ionisation phenomena and potential energy surfaces for simple organic reactions.

And the Clark group thereby uncovered a flaw in the IBM software! The NUMAC computer was being used as a testbed for system development by IBM and the University of Michigan, which had pioneered the multiple access (virtual machine) MTS aspects of the IBM 360/67 computer. In one of our 8-hour shifts we had initiated a series of ‘chained’ jobs under IBM’s experimental CP/CMS operating system. This required the construction of a symmetry matrix, to decide which two electron integrals were not zero. The subsequent construction of a matrix computed over gaussian functions and the subsequent diagonalisation to self consistency. Chained jobs needed to be scheduled in strict order, but the IBM operating system recognised them only by the first job in the chain. We ran the the computer over a Sunday night and handed it over to the regular operators on Monday morning - and the later jobs in the chain were still running. Much to the consternation of all concerned, the jobs continued for a further hour since there was no way to stop them. This led to a lot of difficult questions for IBM software developers and a ban by NUMAC on the use of the chain facility.

A third aspect of my research led to the formation of a team studying the fourth state of matter through researches in plasma science and technology. By researching the phenomena characterising the weathering and ageing of polymers, the team became one of the first to recognise the challenges of environmental issues.

In those days, a request by another group of researchers for a hard-copy reprint of a research paper was a mark of scientific esteem and an eye-catching logo on every reprint, such as on the example below, seemed a good way of getting my research group better known worldwide. Amused feedback and occasional reproductions with acknowledgement suggested that the strategem had worked.

During my time in Durham I was able to establish interdisciplinary collaborations with other University departments on the Science Laboratories site. Applied Physics shared an interest in the mean free paths of electrons in Langmuir-Blodgett films as a function of kinetic energy, Botany collaborated in the evaluation of protein quality as a measure of nutritional value in the quest to improve food for emerging nations, Engineering shared an interest in interface studies of tribological surfaces and Physics (Professor Brian Tanner) joined Graham Beamson (a senior demonstrator in chemistry associated with my group) and Joe Howard Joe Howard's Research Group to develop advanced instrumentation for laboratory-based extended X-ray absorption fine structure (EXAFS).

Ironically, the Royal Society of Chemistry made me its Tilden Medallist for 1984, the year after I left Durham University. The award was made for my contributions at Durham to research in X-ray photoelectron spectroscopy - particular mention being made of applications to polymer surfaces, plasma science and technology, and ab initio studies in physical organic chemistry and XPS.

For David Clark's account of his subsequent career in industry, click here.

research_groups/prof._david_t._clark.txt · Last modified: 2016/05/26 14:32 (external edit)
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