3-D Effects on Tokamak Plasma Stability

Lead Research Organisation: University of York
Department Name: Physics

Abstract

I graduated from Loughborough University with a BSc in Mathematics back in 2017, submitting my dissertation on "Optimal Route Across Hilly Terrain". I then worked as a software developer in the insurance industry for a couple of years before scrapping the corporate life to continue pursuing academia, with the objective of doing something that suits my interest in visual, physical applications of mathematics as well as making a positive impact on the planet. This led me to pursue a PhD, in particular within the Fusion CDT due to the ever increasing need for alternative energy sources as our hunger for energy grows.
ELMs (edge-localised modes) are violent eruptions that occur at the edge of plasmas. If uncontrolled, they will cause excessive erosion on next step tokamaks; for example ITER will only be able to survive ~10 of the largest ELMs before the damage will put it out of action for extended maintenance. On ITER, it is planned to apply 3D magnetic perturbations as an approach to control these ELMs.
I will be working with the ELITE code - an ongoing collaboration between the University of York and General Atomics, recently extended to calculate the plasma response to these 3D magnetic perturbations and the resulting 3D equilibrium.
My research will have a focus on "3D Effects on Tokamak Plasma Stability" and will be supervised by Prof. Howard Wilson. In particular some of my objectives are;
-Benchmarking the new 3D ELITE code against other approaches.
-Using ELITE in order to develop an understanding of how ELMs and the pedestal region are influenced by 3D effects.
-Further extending the model to include non-ideal effects such as plasma resistivity.
-Explore the effects of a conducting wall around the plasma.
-Explore the consequences for equilibria characteristic of the STEP and ITER plasmas.
Research into these areas is extremely important as it will allow us to better understand how to control or avoid ELMs, which is vital for the lifespan of next step tokamaks and hence development of fusion energy.

Planned Impact

Identifying a sustainable energy supply is one of the biggest challenges facing humanity. Fusion energy has great potential to make a major contribution to the baseload supply - it produces no greenhouse gases, has abundant fuel and limited waste. Furthermore, the UK is amongst the world leaders in the endeavour to commercialise fusion, with a rapidly growing fusion technology and physics programme undertaken at UKAEA within the Culham Centre for Fusion Energy (CCFE). With the construction of ITER - the 15Bn Euro international fusion energy research facility - expected to be completed in the middle of the 2020's, we are taking a huge step towards fusion power. ITER is designed to address all the science and many of the technology issues required to inform the design of the first demonstration reactors, called DEMO. It is also providing a vehicle to upskill industry through the multi-million pound high-tech contracts it places, including in the UK.
ITER embodies the magnetic confinement approach to fusion (MCF). An alternative approach is inertial fusion energy (IFE), where small pellets of fuel are compressed and heated to fusion conditions by an intense driver, typically high-power lasers. While ignition was anticipated on the world's most advanced laser fusion facility, NIF (US), it did not happen; the research effort is now focused on understanding why not and the consequences for IFE, as well as alternative IFE schemes to that employed on NIF.

Our CDT is designed to ensure that the UK is well positioned to exploit ITER and next generation laser facilities to maximise their benefit to the UK and indeed international fusion effort. There are a number of beneficiaries to our training programme: (1) CCFE and the national fusion programme will benefit by employing our trained students who will be well- equipped to play leading roles in the international exploitation of ITER and DEMO design; (2) industry will be able to recruit our students, providing companies with fusion experience as part of the evolution necessary to prepare to build the first demonstration power plants; (3) Government will benefit from a cadre of fusion experts to advise on its role in the international fusion programme, as well as to deliver that programme; (4) the UK requires laser plasma physicists to understand why NIF has not achieved ignition and identify a pathway to inertial fusion energy.

As well as these core fusion impacts, there are impacts in related disciplines. (1) Some of our students will be trained in low temperature plasmas, which also have technological applications in a wide range of sectors including advanced manufacturing and spacecraft/satellite propulsion; (2) our training in materials science has close synergies with the advances in the fission programme and so has impacts there; (3) AWE require expertise in materials science and high energy density plasma physics as part of the national security and non-proliferation strategy; (4) the students we train in socio-economic aspects of fusion will be in a position to help guide policy across a range of areas that fusion science and technology touches; (5) those students involved in inertial fusion will be equipped to advance basic science understanding across a range of applications involving extreme states of matter, such as laboratory astrophysics and equations of state at extreme pressures, positioning the UK to win time on the emerging next generation of international laser facilities; (6) our training in advanced instrumentation and control impacts many sectors in industry as well as academia (eg astrophysics); (7) finally, high performance computing underpins much of our plasma and materials science, and our students' skills in advanced software are valued by many companies in sectors such as nuclear, fluid dynamics and finance.

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S022430/1 01/10/2020 31/03/2028
2440150 Studentship EP/S022430/1 01/10/2020 30/09/2024 Luke Thompson