Determining the role of plasma-molecule interactions on tokamak power exhaust (plasma strand project)

Supervisors: Dr Kirsty McKay (University of Liverpool), Kevin Verhaegh / James Harrison (UKAEA)

In present-day tokamak experiments, there is strong evidence the interactions between plasma, atoms and molecules plays a key role in power and particle exhaust, in particular access to regimes that exhibit strong dissipation of plasma particles, momentum and energy before they reach the surfaces of the divertor.

These interactions are highly complex, involving neutral uncharged atoms and molecules and molecular ions such as D2+ and D2, which are not fully or accurately captured in state-of-the-art predictive tools to simulate exhaust in tokamaks.  In recent experiments on MAST-U, these interactions were found to strongly affect the interpretation of data from experiments and interpretive simulations.

This project aims to study the role of the interactions between the plasma, atoms and molecules through dedicated experiments on MAST Upgrade and simulations spanning operating regimes accessible to MAST-U and future reactors such as STEP.  Novel spectroscopic measurements of Deuterium Fulcher band emission will be made in the MAST-U divertor with uniquely high time resolution at varying states of particle and power dissipation in the divertors in steady-state and during transient phenomena.  Novel analysis techniques will be developed and applied to ascertain the role of the fundamental interactions at work, including Molecular Assisted Recombination, Molecular Assisted Ionisation, Molecular Assisted Dissociation.

In parallel, simulations will be performed with the SOLPS-ITER code to study the impact of the interactions observed in experiments on predicted plasma states, and the ability of the code to reproduce the measurements made in experiments.  This will require novel synthetic diagnostics to be produced that includes the relevant atomic and molecular data and an accurate description of the optical spectroscopy diagnostics.

The student will gain both computational, analytical and practical experience around Tokamaks, and will be able to participate in group and conference style meetings, allowing them to develop presentation skills, and gain academic writing experiences. While a PhD is an individual pursuit, the research aspects of fusion are very much based on team working and communication skills will be developed throughout the PhD time. 

The project will be based mainly at Culham in Oxfordshire, but there will be opportunities for travel to conferences, and collaborations. 

This project is offered by University of Liverpool. For further information please contact Dr Kirsty McKay ( or Dr James Harrison (

This project may be compatible with part time study, please contact the project supervisors if you are interested in exploring this.