Research Fellows Directory
Professor Bruce Lipschultz Fellow of the American Physical
University of York
My research is in the area of fusion energy, which could serve as an essentially limitless energy source that is both safe and environmentally friendly. The fusion reaction occurs between isotopes of hydrogen (deuterium and tritium), which are at such high temperatures (100 million deg. C) that the electrons have separated from the nuclei (ions), forming a plasma, or ionized gas. We confine the plasma away from the reactor surfaces by using magnetic fields – a ‘magnetic bottle’ (really a torus) that is called a tokamak; ions and electrons are ‘stuck’ to the magnetic field due to electromagnetic forces which confines them to the core part of the plasma/bottle where the fusion reactions occur. Some fraction of the energy generated leaks out of the bottle onto magnetic field lines that are diverted away form the hot core plasma to be exhausted on heat-bearing surfaces – called the divertor target plates. The width of the diverted heat flux channel to surfaces is very thin (~ 1mm) leading to heat fluxes of order billions of watts per square meter. So how do we get the required greater than 100 reduction in heat flux required to not damage surfaces (< 10 MW/m2)?
To reduce the target heat loads the simplest step is to employ small angles of the magnetic field to the target effects, spreading the heat loads. My research seeks to develop new ideas using magnetic fields to lower the heat flux channel power density further. I have joined a young university team working at the MAST tokamak experiment at the Culham laboratory where a major upgrade will add a ‘Super-X divertor’ configuration, allowing a large increase in the control of the magnetic field and the ability to remove power from that narrow heat flux channel before the power reaches the divertor target. I am embedded in both the MAST-U programme and that of TCV in Switzerland, helping to set research directions and serve as a resource for researchers with relatively little experience in the divertor plasma physics.
Interests and expertise (Subject groups)