Project title: Euratom Fusion Studentship: Fluctuating dynamics of nanoscale defects and dislocations in nuclear materials.
Supervisors: Prof Adrian Sutton, Dr Steven Fitzgerald* and Prof Sergei Dudarev*
At high temperatures, such as those found in fusion reactors, nanoscale defects are observed to have a highly stochastic motion. This is clearly a consequence of thermal fluctuations in the interatomic forces, but the resultant motion is complicated and correlated by strong, long range interactions of the elastic field.These interactions make it prohibitively difficult to construct a reasonably sized state vector for the system; as such despite considerable effort master equation approaches such as kinetic Monte Carlo quickly become unfeasible.
An alternative approach is to integrate the associated stochastic differential equation whose ensemble results are formally equivalent. We are investigating this method, focusing primarily on high temperature pure and impure steels. These materials are of critical importance to the fusion industry but due to the emergence of soft phonon modes have a highly anisotropic elastic field, producing orientation dependent self energies and much more besides.
* Culham Centre for Fusion Energy, Oxfordshire
- Theory and simulation of the diffusion of kinks on dislocations in bcc metals. Swinburne, T. D.; Dudarev, S. L.; Fitzgerald, S. P.; Gilbert, M. R. & Sutton, A. P. Physical Review B, 2013, 87 (6), 064108