Transport of Energetic Electrons and Consequences for Heating and Current Drive – Plasma Strand Project
Supervisors: Dr. Juan Ruiz Ruiz & Professor Roddy Vann (University of York) and Dr. Plamen Ivanov & Dr. Simon Freethy (UKAEA).
Creating the necessary conditions for nuclear fusion reactions to occur requires plasma temperatures of ~ 10 keV (~108 K). Such formidable temperatures can only be achieved by the use of external heating methods of the core plasma. Achieving magnetically confined tokamak plasmas also requires the generation of an electric current in the toroidal direction (plasma current). The use of high-power microwaves for heating and driving the plasma current is the most promising alternative that scales well to reactor-scale plasmas and benefits from established expertise both experimentally and theoretically.
Heating and driving a plasma current by using high-power microwaves relies on the transfer of energy from an electromagnetic wave to electrons (wave damping). In the process, a population of highly-energetic electrons is generated, which ultimately heat the thermal bulk of the plasma by collisions. The process is analogous to a resonant pendulum or a spring subject to external forcing. Current models and numerical codes assume an ideal transfer of energy from the wave to the electron, in the absence of any plasma fluctuations. Despite the fact that plasma fluctuations from turbulence are ubiquitous to all magnetically confined fusion plasmas, the effect of turbulent fluctuations on the heating and current drive from externally launched microwaves has never been explored in detail.
The aim of this project is to assess the effect of turbulent fluctuations on the heating and plasma current generated via heating in the electron-cyclotron range of frequencies. After becoming familiar with established theory and models of wave heating, the student will use state-of-the-art numerical turbulence simulation codes to assess the effect of turbulent fluctuations on a population of energetic electrons. The student will quantify how energetic electrons are diffused by the turbulence, and will incorporate this diffusion into established wave-heating models and codes. The ultimate goal will be to quantitatively predict, for the first time, how turbulence affects heating and current drive in reactor-scale plasmas such as ITER and STEP.
The student will present this work internally and in international conferences and workshops, and will produce publications in high-impact, internationally recognized journals. An emphasis will be placed on acquiring communication skills, both oral and writing, as well as in establishing collaborations with partner institutions, .e.g. UKAEA, Tokamak Energy, University of Oxford, and/or EPFL.
The project is expected to be primarily based at the University of York, with potential visits to collaborating institutions (e.g. UKAEA, Tokamak Energy, University of Oxford, and/or EPFL).
During the first six months of the PhD plasma strand students will typically travel to undertake taught modules at all of the Fusion CDT partner universities.
This project is offered by University of York. For further information please contact: Juan Ruiz Ruiz (juan.ruizruiz@york.ac.uk), Plamen Ivanov (plamen.ivanov@ukaea.uk), Simon Freethy (Simon.Freethy@ukaea.uk), Roddy Vann (roddy.vann@york.ac.uk).
For details on how to apply, please visit: Apply