Mapping the engineering of plasma- and high heat flux induced failure modes in plasma-facing divertor components for future fusion reactors

About the Project

Mapping the engineering of plasma- and high heat flux induced failure modes in plasma-facing divertor components for future fusion reactors

A funded 4-year UK EngD studentship is available at the University of Birmingham with a tax-free stipend. The project is collaborated with Forschungszentrum Jülich in Germany, with industrial partnership with US’s Electric Power Research Institute (EPRI)

Background:

Fusion energy demonstration critically depends upon success of plasma-facing armour capable of protecting the back-end systems and successful demonstration of divertor exhaust performance under power-plant relevant extreme conditions. There are, however, several critical challenges remain to successfully design plasma-facing components (PFCs). Firstly, steady-state plasma- will cause severe near-surface degradation of PFCs due to unprecedented plasma particle fluxes comprising of deuterium, tritium, helium and other impurities (>10²⁴ particles.m^-2s^-1 in the divertor). Secondly, impurity seeding of plasma to improve performance will further degrade component erosion/redeposition issues. Thirdly, this is critically tied to very high temperature operations (>800 C and upto component’s melting point) concomitantly worsened by steady-state heat loads (up to ~15 MW/m²). Fourthly, transient heat loads, going up to a few GW/m² pose a major structural damage challenge under plasma disruptions (vertically displaced electrons, runaway electron beams, mitigated & unmitigated edge localized modes to name a few) PMI also causes enhanced near-surface tritium retention in W, which is deleterious to fuel sufficiency requirement. And lastly, all of the points above lead to a severe case of tritium retention in near-wall structures, dust formation that further traps tritium and potential safety risks (toxic radioactive WO₃ formation as an example). Therefore, separate effects study and combined synergistic studies are essential to map PFC performance and generate robust engineering frameworks where all degradation modes are quantified – this is currently not the case which this EngD will evaluate in close partnership with EPRI and Julich. The UK currently does not host any fusion facility where power-plant relevant plasma fluxes and heat loads can be applied to PFC components. You will address this issue by building upon existing Birmingham-Julich research programmes and using Julich’s power linear plasma devices and heat flux facilities.

Proposed Work Scope: This study will focus on developing an engineering understanding of the effect of fusion-relevant plasma exposure and extreme heat loads on mapping PFC failure modes and generate a PFC structural integrity database plus a model to aid divertor designs. Database for PFC failure under combined plasma extremes is currently unavailable in the fusion community, with very little data collated with EUROfusion. To quantify interplay between different plasma species, and the further impact of impurity seeding that is critical for benchmarking erosion rates, candidate PFCs with different wall materials will be exposed to deuterium and mixed plasma scenarios at PSI-2 over a wide temperature range. Post exposure examination (PEE) of uncooled or actively cooled PFC components, combined with AI/ML techniques, will be aimed to generate key engineering knowledge of near-wall component failure under steady-state DD, steady state DT and under large disruption scenarios. You will also have opportunity to collaborate with US and French tokamak facilities such as D-IIID and WEST @ CEA-Saclay

Supervision and International Collaborations: You will be based at the University of Birmingham, and will be collaborated with researchers from Jülich, and EPRI. This project will involve multi-national collaborators, and so you will have a unique opportunity to work with renowned experts from world-recognized institutes in Germany, the UK and the US.

Who we are looking for:

A first or upper-second-class degree in an appropriate discipline: materials science and engineering, nuclear/chemical/mechanical/aerospace engineering, physics, plasma-physics, condensed-matter physics. No prior experience is mandatory. Some exposure to microstructural characterisation, hydrogen materials interaction and/or, fission/fusion basics would be advantageous.

A self-motivated, inquisitive, genuine and driven individual.

Contact:

Please contact Professor Arunodaya Bhattacharya – a.bhattacharya.1@bham.ac.uk, Dr. Andrew Sowder (asowder@epri.com) or Dr. Jan W. Coenen (j.w.coenen@fz-juelich.de) to discuss your motivation. Include the following: CV and transcripts.