Prof Philippa Browning - postgraduate opportunities
Solar coronal heating by reconnection and relaxation events: A long-standing unsolved problem in solar physics is to explain how coronal plasma is heated to temperatures of millions of degrees. An attractive idea is that the underlying physical process is the same as that causing solar flares, and thus the hot corona results from a superposition of many “nanoflare” events. The process of magnetic reconnection underlies such events, and also occurs widely in other astrophysical and laboratory plasmas. PhD projects are available to model this process, both using analytical and simple numerical models, based on relaxation theory, and using 3D magnetohydirdynamic simulations.
Acceleration of charged particles in magnetic reconnection:Magnetic reconnection is difficult to observe directly, but an important observational signature is the acceleration of charged particles, and a student could develop models of the energy spectra and other properties of charged particles in reconnection, comparing these with observational data from the RHESSI satellite. A novel feature of the project will be the study of 3D magnetic reconnection configurations. This is of particular relevance to solar flares, as a significant proportion of the energy release in these events is carried by high energy non-thermal charged particles, whose origin is not well understood. PhD projects are available to model the acceleration of particles using test particles coupled to MHD models, and novel kinetic approaches.
For both projects, there are strong synergies with modeling magnetically-confined fusion plasmas, and PhD projects may include some element of fusion studies in collaboration with Culham Centre for Fusion Energy.