Dust in magnetized plasmas

Dusty plasmas are ubiquitous: they occur naturally, in fusion, in industry, and as the subject of special laboratory experiments. Magnetic fields can be present in all these areas, but in spite of this, our understanding of the basic dust-plasma physics in the presence of a magnetic field is far from complete.
An improved understanding of magnetized dusty plasmas is particularly important for fusion. In the last few years dust has been recognised as a critical issue for ITER. Solid particles can enter the plasma from the walls or divertor. It is vital to be able to predict the fate of such particles. If they enter the core plasma they rapidly evaporate, thus depositing impurities which can compromise the fusion performance. On the other hand, those which leave the plasma can give rise to serious operational and health and safety problems.
We propose a collaborative and unified programme of theoretical, computational and experimental work on dust in magnetized plasmas, involving Imperial College and the Universities of Liverpool, York. Although the main emphasis is on fusion applications, the work would benefit other areas, for instance the industrial plasma community.
The proposed research covers three overlapping areas: (1) the effect of magnetic fields on the basic dust-plasma interaction, (2) the interaction of dust with magnetically driven filaments, particularly in the tokamak edge, and, (3) improved tokamak dust transport simulations. As part of the project a new high magnetic field dusty plasma experimental facility will be set up at Liverpool.

This project concerns magnetized plasmas which contain dust. Such plasmas occur in space, fusion, industry, special laboratory experiments. The main application of the work which we will study in detail is fusion. However, improved understanding of the basic physics of such plasmas is potentially important for other applications, and we will initiate dialogues with those in other communities to publicize our work and try to assess its possible significance.

From the perspective of the EPSRC strategic themes, this project falls under the headings of: Energy, and Future Manufacture.

The international fusion programme is entering a crucial phase with the construction of the next-step global fusion experiment, ITER. This tokamak reactor, in which the first plasma will be created in 2019, should achieve net energy gain. It aims to investigate many of the science and engineering issues vital to a working fusion power station. The deleterious effect of dust is one of these issues. Looking beyond the university plasma physics community, we therefore plan to get more closely involved in the ITER programme, using our existing contacts and by presenting our work at international fusion conferences. Securing ITER recognition is an essential part of the present project.

Plasma based devices are finding increasing uses in industry, notably for applications involving materials processing and surface engineering. Plasma technology is both enabling, allowing new processes to be exploited, and more environmentally friendly than older technologies. Discharges involving magnetic fields, for instance magnetrons, are routinely used, and our work will be directly relevant to the basic physics of such devices. In order to assess the potential importance of this work we plan to promote it within the technological plasma community, e.g., by attending specialist conferences in this area. The University of Liverpool also has close ties with this community which we plan to exploit.

With regard to public outreach, we will ensure that all the post-doc's on this grant attend appropriate courses on public engagement, and we will work with the Media and Communications offices at the participating Universities to promote public awareness of the project.