I completed my undergraduate degree in Materials Science at the University of Oxford, with my Master’s project based on characterisation of magnesium diboride superconductor for medical applications. I am now undertaking a DPhil entitled ‘Nanoscale chemistry and radiation damage in Nb3Sn superconducting wires for fusion machines’ supervised by Prof. Chris Grovenor and Prof. Michael Moody at the University of Oxford.
Niobium-tin’s superconducting properties were discovered in the 1950’s, but most medical applications, and the Large Hadron Collider, use niobium-titanium wires for the large magnets as it is easier to process and much cheaper. However, niobium-tin has a higher upper critical field so is the ideal candidate for the main coils of the ITER fusion reactor. In that application the wires will be exposed to significant doses of high energy neutrons.
Despite the excellent, and rapidly improving performance of the latest niobium-tin wires in high magnetic fields, the complex multi-phase microstructure is not fully characterised, especially important features like grain boundary segregation. My project will primarily use Atom Probe Tomography (APT) to provide atomic scale spatial-chemical characterisation of these superconducting wires. Furthermore, I will utilise Transmission Kikuchi Diffraction (TKD) to analyse the orientation and crystal structure within the wires. Different additions, such as titanium, zirconium and tantalum, will be analysed in samples provided by Florida State University, and hopefully neutron-irradiated samples from Vienna as well.
This multi-technique approach will aim to provide vital information to determine the optimal microstructural conditions of Nb3Sn wires needed for a fusion reactor.