Careers

PhD and MSc opportunities

PhD student Depending on resources, we aim every year to have new PhD and MSc projects with several UK universities addressing plasma physics, materials science and fusion engineering associated with tokamaks, providing a range of exciting research opportunities.

The projects range from the theoretical, through computational modelling, to experimental studies. Most students are based at Culham Centre for Fusion Energy, while some are based at their university. All have both a Culham and a university supervisor.

Typically starting each October, we run a broad range of PhD and MSc projects with about eight different university departments. Please check this page for updates on opportunities.

Current opportunities

3-D simulation of microwave propagation, scattering and mode-conversion in tokamak plasmas – Fusion Doctoral Training Network, University of York

EPSRC CASE PhD studentship in nanofluids as coolants for future fusion reactors – Mechanical Engineering Department, Imperial College, London

PhD in 3-D simulation of microwave propagation, scattering and mode-conversion in tokamak plasmas

Fusion Doctoral Training Network, University of York

Closing date for applications: until the position is filled

Project starting date: by 30/09/13

Microwave radiation is used widely to diagnose tokamak plasmas:

imaging spontaneous thermal emission can give spatially-resolved measurements of rapid changes in the plasma temperature (which can reveal the dynamics of various long-wavelength instabilities);
imaging the signal that is returned when a (low power) beam is reflected / back-scattered from a cut-off surface can tell us about fluctuations and turbulent flows at that surface;
in sufficiently dense plasmas (which are common on spherical tokamaks such as MAST), the microwave emission is strongly anisotropic, and this anisotropy can be used to deduce the field line pitch and thence the edge current density, which is not routinely measured by any other techniques and is a key parameter to develop and constrain theories for plasma stability.

Equally importantly, the injection of high power (megawatt) microwaves is used to heat and drive currents in the tokamak plasma.

However, real-life tokamak plasmas have non-monotonic density profiles. Not only do some instabilities manifest themselves through the generation of density blobs or filaments, but also the plasma is turbulent. These fluctuations can exist on lengthscales comparable with the microwave wavelength; these structures scatter the microwaves - complicating interpretation of diagnostic data and de-focusing heating beams. Ray-tracing of the microwaves is not applicable, and so a "full-wave" simulation approach must be followed. This is apparently evidenced by a novel York/CCFE microwave imaging diagnostic currently installed on MAST which observes high fluctuation levels, even during apparently quiet periods of plasma operation.

York has developed a 3-D full-wave code to simulate the propagation of microwaves through realistic plasma profiles: the image top-right shows a simulation of a microwave beam being scattered by a density filament. This PhD project will use this code to study the effect of realistic turbulence on the microwave propagation. We will also employ a code originally written for studying laser-plasma interactions to model, for the first time, the propagation of so-called electron Bernstein waves (which are particularly important for spherical tokamaks such as MAST but are challenging to simulate because one needs to evolve the distribution function itself). With this comprehensive toolbox we will tackle physically relevant problems of importance to both the heating and diagnostic microwave communities.

This PhD project is part of the Fusion Doctoral Training Network (FDTN), which provides a comprehensive training programme in plasma physics and fusion energy science. For the first six months or so, the successful candidate will undertake, as part of the FDTN cohort, a range of taught modules and other activities to enable him/her to become an effective researcher.

This four-year PhD studentship has guaranteed funding to start on 30 September 2013. The studentship is fully-funded for applicants ordinarily resident in a member state of the European Union (including the UK): the funding will cover university tuition fees and additionally provide a stipend of approximately £16,135. (An applicant who is not normally resident within the EU is eligible for this award, but would have to provide evidence that (s)he can finance the university fee differential, which is approximately £12,170 per annum.)

For more information and application details please see the University of York website.

EPSRC CASE PhD studentship in nanofluids as coolants for future fusion reactors

Mechanical Engineering Department, Imperial College, London
in collaboration with Culham Centre for Fusion Energy

Closing date for applications: 30/05/13

Project starting date: by 01/10/13

The engineering of a commercial fusion reactor has to address the extreme heat fluxes at different parts of the plant. These heat fluxes may be at the limit of what is currently possible to remove with existing cooling approaches. However, it is easier to tolerate high heat fluxes in water-cooled designs, and water also allows the use of conventional PWR generating technology. Therefore, if water-based systems can be developed that can remove higher heat fluxes and operate at higher temperature, the engineering of fusion reactors may become simpler and the more cost-effective.

Nanofluids are mixtures of liquids with nanoparticles (e.g. water with Titanium dioxide - different ceramic powders and carbon nanotubes have been tested) and it is an area of research that has been initiated in the last 15 years. Tests during this period have shown that Nanofluids lead to around 5 times increase of the heat transfer coefficient (either conduction or convective heat transfer coefficient) when compared to that of pure liquids. Research so far has been chiefly in conduction and convection heat transfer but there is some evidence that the critical heat flux for boiling is increased when Nanofluids are used. These heat transfer characteristics of Nanofluids can contribute to a step change in the design of heat exchangers in many different cooling applications, including for fusion reactors.

Reported experiments in the literature are limited to measurements of integral quantities rather than the microscale behaviour of nanofluids, which means that the associated physics responsible for the observed improvements of heat transfer are not understood. In addition, theoretical attempts to predict heat transfer in nanofluids are limited by the selected modelling process, which is uncertain without knowledge of the underlying physics. Therefore, the project will focus on obtaining new understanding of the physics at the microscale and the macroscale behaviour of flows of nanofluids. This understanding is necessary for future development of optimised designs.

The project will develop further existing laser-based experimental techniques for optical measurements of liquid temperature, nanoparticle size and velocity and apply them in simplified flows of nanofluids with controlled operating conditions. The experimental measurements will be assisted by Molecular Dynamics computations of Nanoparticles dispersion in order to identify the new physics responsible for improved heat transfer. The final outcome is to provide design guidelines for the use of nanofluids for cooling of future fusion reactors in collaboration with a team at Culham Centre for Fusion Energy.

The candidate must have an interest in Fluid Mechanics and Heat Transfer and be willing to learn more about the operation of optical measurement techniques and Molecular Dynamics simulations and develop them further for application to Nanofluids. Knowledge of computer programming (i.e. FORTRAN or C/C++) is essential.

The project is available to UK students and EU students who have obtained their first degree in UK. 2.1 or 1st class Engineering or Science degree is required. Applications to: Prof. Y. Hardalupas (y.hardalupas@imperial.ac.uk) and Professor A.M. Taylor (a.m.taylor@imperial.ac.uk) and Dr. Tom Barrett (tom.barrett@ccfe.ac.uk).