I joined the United Kingdom Atomic Energy Authority's (UKAEA's) Fusion Theory and Modelling Department in September 2000, after obtaining a Ph.D. from Edinburgh University for theoretical studies of foam and emulsion behaviour, and following a carefully considered job search. That care was well rewarded as my job provides me with the opportunity to do theoretical research on a challenging and interesting topic, whilst providing a good salary and stable employment. I am also able to work on a subject I believe in; fusion's potential to provide a long-term, non-global-warming energy supply makes it rewarding, goal-oriented work.
Fusion is the method by which the sun and the stars produce energy, and if harnessed on Earth it has the potential to provide a safe and effectively unlimited source of power. Fusion is the process whereby the nuclei of two small atoms, such as hydrogen, join to form a single larger atom. When the small nuclei of hydrogen isotopes "fuse", they produce helium and also give off a large amount of energy (over a million times more energy than by burning an equivalent mass of coal).
The fuels used for fusion are abundant, and the helium produced by fusion is a harmless gas that won't contribute to global warming. These factors mean that fusion has great potential to provide a harmless and sustainable method for long-term power production. Unfortunately, temperatures in excess of those in the sun are required for fusion to occur on Earth, making fusion power production a challenge.
The most successful strategy for producing fusion energy in a sustained and controlled way uses strong magnetic fields to hold a hot charged gas (a "plasma") within the interior of a hollow donut-shaped device. The magnetic fields keep the hot plasma away from the vessel's surrounding walls and enable us to heat plasmas to the temperatures and pressures at which fusion will occur.
The European Flagship JET experiment operated by UKAEA in Oxfordshire is able to sustain temperatures 10 times hotter than the sun for over 10 seconds. In the conditions produced in JET, fusion has been demonstrated on Earth.
The most successful device to date is the Joint European Torus (JET), an experiment that is operated by UKAEA for teams of European scientists at Culham Science Centre in Oxfordshire. JET regularly produces in excess of 50 metres cubed of plasma at temperatures 10 times hotter than the centre of the sun. These temperatures may be sustained for 5 to 10 seconds, enabling fusion reactions to be studied.
The hot plasmas produced within fusion devices have many exotic properties, and understanding their behaviour involves calculations and techniques at the forefront of our current understanding. For example, my work uses advanced theoretical techniques developed at Culham to determine how a flow of the plasma (around JET's donut-shaped interior) will alter the maximum pressure at which the plasma may be contained.
My current work is entirely unrelated to that of my PhD, neither the methods used nor the subject studied have much in common with those contained in my PhD thesis. I was employed on the basis of my successes in my previous field and my capacity for learning new skills. Nonetheless, fusion is a mature subject, and I have found it a challenging but rewarding area to move into.
A spherical plasma from the MAST device.
To maximise the performance of a fusion power plant, we must determine the most extreme conditions under which a fusion plasma may be confined. This is epitomised by another experiment, the Mega Amp Spherical Tokamak (MAST), designed and operated by UKAEA at Culham. MAST is a more spherical device than JET, and if the design is successful it will have advantages over traditional fusion power-plant designs. Although promising, aspects of MAST's performance are as yet unproven, and this is a subject of our ongoing research.
The next step after JET will be the International Thermonuclear Experimental Reactor (ITER), the result of a worldwide collaboration of nations and fusion research scientists. ITER will be a power-plant scale device and will operate for tens of minutes whilst demonstrating a production of fusion power that is 10 or more times greater than the power used to heat the plasma. ITER is the last step before a prototype power plant "Demo", and will enable us to test and develop the necessary materials technology for a power plant's economically successful operation.
Meanwhile, at Culham my day typically starts at 8.30 a.m., following a 25-minute cycle from the pretty local town of Abingdon. I usually work until 5 or 6 p.m. The department is friendly and multinational, and collaborative work is the norm. Many of the department's members have world-wide collaborations, and the work often involves presenting material at conferences, attending summer schools, and visiting other research centres to collaborate on work. Since joining I've attended two summer schools, one in the idyllic German town of Bad-Honnef near Bonn, and a conference in Manchester.
Work and Study at Culham
Various career opportunities (full-time employment and PhDs) are available in fusion research at Culham at the present time. You can register your interest on the 'Opportunities in fusion with UKAEA' contact form on the fusion Web site.
Not all the work at Culham is theoretical like mine. In fact the majority of UKAEA's employees at Culham work on the two large experiments MAST and JET. Indeed, there are normally opportunities for physicists and engineers (electrical, electronic, and mechanical). Although some knowledge of plasma physics, materials science, or vacuum technologies is useful, it is by no means essential. The recent government review of the UK fusion programme was very favourable, and in recognition of its scientific value, our funding will shortly be redirected from the energy budget to the research budget of the Department of Trade and Industry. This will enhance our links with universities and other UK research laboratories. We also get a lot of additional funding from Europe--fusion research is very international.
My future work will increasingly focus on many of the challenging and fascinating questions in fusion materials science, whose resolution will enable the successful exploitation of fusion as a power source for future generations. I will also plan to study fundamental aspects of fluid turbulence, as turbulence strongly affects the efficiency of our current fusion devices.
Once the construction of ITER is approved, fusion research will receive a massive boost. Engineers and scientists will be required to build, maintain, and run experiments at this new research facility, although it is anticipated that remote participation in experiments may be possible from fusion laboratories such as ours. In the meantime, experiments using JET are ongoing, and studies using MAST are intended to run for many years yet.