York Plasma Institute - Staff, Postdocs and Postgraduate Students

Lecturer

Dr James Dedrick

CDT Deputy Program Director & Senior Admissions Tutor
Senior Lecturer

Mrs Ella Eyre

ella.eyre@york.ac.uk

Mrs Hillary Marshall

hillary.marshall@york.ac.uk

Mrs Katy Welford

katy.welford@york.ac.uk

Andrew Malcolm-Neale

a.malcolmneale@york.ac.uk

A

Joel Adams

I earned my undergraduate degree in Computer Science from Aberystwyth University in 2021. Subsequently, I dedicated two years to working in the financial industry as a software developer. During this period, I developed a strong interest in fusion energy and decided to pursue further studies at the Fusion CDT in York. I am currently undertaking a Ph.D. program with a focus on X-ray generation in high energy density plasmas under the guidance of Dr. Christopher Ridgers.

High power lasers produce extremely strong electromagnetic fields in their focus. The fields rapidly strip electrons from atoms to produce a plasma. These electrons can strongly radiate x-rays by bremsstrahlung. These x-rays are very useful for radiographing dense material and have been proposed as a diagnostic tool for ICF experiments. In ICF a driver is used to compress DT fusion fuel capsules to high density and temperature. This compression is unstable and deformations of the spherical fuel capsule inhibit fusion performance. Solving this is a major research question in ICF but is difficult due to a lack of diagnostic information about the shape of the compressed fuel. My project will include utilising machine learning techniques applied to EPOCH, a particle-in-cell simulation software, to explore how we can control laser-driven bremsstrahlung sources to better review how the fuel compresses. This endeavour is anticipated to serve as the foundation for an Orion experiment at the AWE.

Council bio:

I earned my undergraduate degree in Computer Science from Aberystwyth University in 2021. Subsequently, I dedicated two years to working in the financial industry as a software developer but have now returned to university to do a PhD in Nuclear Fusion. Motivated by a commitment to the well-being of fellow students, I am drawn to the role of PGR Students’ Officer. I seek to address pertinent issues affecting PGR students at the University and within the GSA, fostering an environment conducive to academic success and personal growth.

 Ethan Attwood

After a winding path that included materials science and medicine, I completed an integrated masters in Natural Sciences from the University of East Anglia. I then worked in London for four years as a data science consultant and software engineer, helping to build internal search engines for enterprises. The desire to pursue independent research to improve the world never quite left me however, so in 2021 I applied for an MSc in Fusion Energy at the University of York. This was an incredibly rewarding experience, and confirmed that returning to physics for postgraduate study was the right move.

My PhD project will be with Drs Peter Hill, David Dickinson and James Cook (UKAEA). Understanding the edge region of magnetically-confined fusion plasmas is critical to determining the operation of the entire device, and also presents some of the most complex physics. Multiple models such as particle-in-cell and finite elements are required to fully simulate this volatile region. My project comprises two main objectives, first to investigate how these models can be coupled together, and secondly to quantify the physical uncertainty in their results. This will use state-of-the-art supercomputing from ExCALIBUR, an ambitious project to bring UK research into the next generation of exa-scale computation.

B

Lloyd Baker

After I graduated from my undergraduate degree with the Open University, I attended a tour of the Culham Centre for Fusion Energy (CCFE). I really enjoyed electromagnetism during my prior studies, and the prospect of applying this to solving the global energy crisis was incredibly exciting. This drove me to pursue further education in plasma physics and fusion at the University of York where I completed my Masters in Fusion energy. My MSc project brought me back to CCFE where, using a novel spherical harmonic method formulated by Dr Oliver Bardsley, I designed a computational tool to optimise poloidal fields within the MAST-U tokamak.

Plasma exists outside of tokamaks in many forms with a variety of applications. My project will focus on negative ion production in low-temperature plasmas. Negative ions are used in neutral beam injection to heat fusion plasmas and drive current. Beyond fusion, they have uses in areas such as spacecraft propulsion and surface processing. With my supervisors James Dedrick, Chris Ridgers and Erik Wagenaars, I'll be further developing a massively parallelised, fully kinetic particle-in-cell simulation tool with a robust reaction chemistry set to describe low-temperature hydrogenic plasmas. This tool will then be used to investigate novel areas of plasma research.

Mike Battye

I completed my undergraduate degree in Physics at the University of York in 2017. Afterwards, I decided I wanted to work with people with complex needs such as brain injuries and found this incredibly rewarding. In 2018, I started my career in data roles, first in a clinical trials testing laboratory and then at a medical and temperature-controlled packaging company. In 2020, I worked at a medical imaging software start-up in Oxford where I helped build deep learning neural network models to delineate structures within CT and MR scans. From 2022, I have worked as a data scientist within a nuclear engineering industry, making this transition because I have always been interested in fusion energy since university. This led me towards the Fusion CDT after I found a project which fit both my data skills and physics knowledge.

Divertors are a key aspect within MCF, especially in spherical tokamaks using a H-mode plasma. The divertor is able to handle plasma effects beyond the X-point via exhausting impurities and removing heat. It will therefore encapsulate an area of the tokamak in which key diagnostics can be found. However, currently, the divertor is a very complex component to design, model and control. Therefore, there is a need to develop a digital twin of the divertor to capture models and data to provide a more complete picture of the reactor. This will help understand the state of the materials and components, alert users to predictive maintenance and run what-if scenarios using models of the plasma and plasma-facing materials. A key aspect of the hybrid modelling approach will be quantitative validation of multi-physics and data-driven models and establishing credibility in failure predictions through physical testing and quantifying uncertainty. These will be very useful skills for future design, manufacturing, implementation and through-life management of future fusion energy plants.

This PhD project is being co-funded by Assystem, a global nuclear engineering company with specialities in engineering, digital and project management. Assystem has knowledge and experience in both nuclear fission and fusion such as supporting UKAEA's fusion experiments in Culham and in its role as architect engineer for ITER.

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Claudia Cobo Torres

Having completed an MSci degree in Physics at Imperial College London and presented my final year project on the characterisation of gas targets for laser wakefield accelerators, I am now starting my PhD at the York Plasma Institute under the supervision of Dr. Chris Murphy. My project is titled “Understanding laserplasma interactions through wakefield acceleration experiments”.

The interaction between an intense laser and plasma results in non-linear instabilities which can accelerate particles to very high energies. Laser wakefield accelerators take advantage of this to allow compact particle acceleration which has the potential to revolutionise high energy photon sources. However, this phenomenon also occurs in laser-driven fusion, where the presence of high energy particles can be detrimental.

I will be studying the evolution of laser-plasma instabilities through experiments at high-intensity laser facilities along with computer simulations. Our findings will be useful in optimising particle acceleration for radiography applications and in better controlling the energy deposition in inertial confinement fusion.

 Bailey Cook

I completed my undergraduate degree in Physics at Royal Holloway, University of London in 2017. Following that, I obtained a PGCE in Physics with Mathematics at King’s College London in 2018, then spent three years working as a secondary school physics teacher. Over those years, I became very interested in energy development, so in 2021 I decided to complete an MSc in Fusion Energy at the University of York. I’m now joining the Fusion CDT to work on turbulence in tokamak plasmas. My project will be supervised by Dr David Dickinson and Dr István Cziegler. 

Plasma turbulence acts to degrade the confinement of particles and energy in tokamaks. Worse confinement leads to the need for larger, more expensive reactors, reducing the efficiency and economic viability of fusion-produced electricity. It’s therefore crucial to understand how turbulent transport arises and how it can be controlled. The primary tools for studying turbulence in hot, magnetised plasmas are non-linear gyrokinetic simulations. My project will involve developing analysis tools for the gyrokinetic code GS2 to explore the structure of spectral energy transfer. It is hoped that these tools will aid the interpretation of existing turbulence diagnostics and inform future experimental efforts.

Cyd Cowley

Having completed a Master’s thesis at Imperial College London on automatic detection and tracking of tokamak impurities, I am currently on a fusion PhD programme led by the fusion CDT and the University of York. The PhD is ‘Modelling of Advanced Divertor Power Exhaust’, and is supervised by Dr. Ben Dudson and Professor Bruce Lipschultz at the University of York, and Dr. David Moulton at CCFE.

The edge interactions between a fusion plasma and the surrounding tokamak components are crucial to the success of an operating tokamak. In particular, edge effects such as the liberation of impurities can lead to detrimental losses of power and efficiency. In an attempt to mitigate these effects, many different divertor configurations have been suggested, including the new Super-X divertor at MAST-U. My current project will centre around modelling transport and power loads for these different divertor configurations, and comparing the predictions made to experimental results.

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Adam Dearling

I graduated from the University of Bath with a Masters degree in Natural Sciences, and now study at the York Plasma Institute under the supervision of Professor Nigel Woolsey and Dr Chris Ridgers.

In my PhD project Plasma Kinetics in Magnetised Laser-Driven Plasmas, I will be investigating the effect of magnetic fields on high-energy-density plasmas. This is motivated by current research that suggests magnetising the hot spot during inertial confinement fusion may help limit conduction losses, a key hurdle in achieving ignition during inertial confinement fusion. However, while the application of magnetic fields may help limit this effect it also introduces other physical effects (for example, Nernst) that are not well understood. Performing reduced complexity experiments to investigate these effects will allow us to benchmark kinetic models of magnetised transport, which can be incorporated into magneto-hydrodynamic simulations. This research can be applied to a variety of problems in magnetised high-energy-density physics.

Lawrence Dior

Before coming to York, I studied Computer Science at the University of Cambridge and worked as a software engineer at Microsoft Research. I decided to further explore my interest in physics, and completed a degree in Mathematics and Physics with the Open University, followed by an MSc in Applied Computational Science and Engineering at Imperial College London.

My PhD project is titled "Extreme Laser-Driven Hydrodynamics", and is supervised by Dr John Pasley. The aim of this project will be to develop a computational model to simulate the hydrodynamic processes that occur during the first few picoseconds of interaction between a high-intensity laser beam and a solid target. These simulations may be compared with experimental data to further our understanding of the initial, non-equilibrium behaviour of such systems. Improving our understanding of laser-plasma interactions could aid in the development of next-generation inertial confinement fusion reactors.

Shaun Doherty

I did my integrated Masters at Newcastle University where I studied Theoretical Physics. My masters project was based around numerically simulating light rays in the region of a black hole. I have had an interest in fusion since before starting university and am very excited to contribute to this area of research.

My PhD project is studying ultra-relativistic plasmas using high intensity short pulse lasers. The physical properties of plasma as it is compressed via lasers are not fully known. At the highest laser intensities currently available the plasma is dominated by ultra-relativistic effects. In this regime the electrons in the plasma are accelerated to relativistic speeds, which causes their mass to increase, in turn causing a phenomenon known as relativistic transparency. The processes by which transparency occurs are poorly understood.

I will be using large scale numerical simulations and making potentially the first time resolved measurements of relativistic transparency in order to gain further insight into the mechanics of highly relativistic plasmas.

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 Yorick Enters

Having completed my MPhys degree at the University of St Andrews, I am now starting my PhD project at the University of York, partnered with the Culham Centre for Fusion Energy (CCFE). My work will focus on using Beam Emission Spectroscopy (BES) as a technique for measuring zonal flows in tokamak plasmas, which will be supervised by Dr Istvan Cziegler (UoY) and Dr Anthony Field (CCFE).

Zonal flows are a major component of tokamak turbulence, which causes strong transport of the plasma across the confining field. Despite this, zonal flows are poorly understood, and detailed measurements are still rare. Thus, the development of an accurate zonal flow measurement technique is crucial for understanding tokamak turbulence and ultimately for improving the quality of global plasma confinement. The measurement technique will be developed using the recently upgraded BES system at the upgraded Mega Amp Spherical Tokamak (MAST-U) in CCFE.  

F

  Joe Fazakerley

I completed my undergraduate degree in Mechanical Engineering at the University of Sheffield in 2019. For the past few years I have travelled a little and worked in various sectors and roles, including in nuclear fission where I worked as a systems engineer on the Hinkley Point C project. I became very interested in fusion during this time and decided to apply for the CDT here at York. Although I did my undergraduate degree in engineering, I have always loved physics and am now very happy to be doing a PhD in nuclear fusion!

My project will be on plasma diagnostics, specifically using the Motional Stark Effect (MSE) to measure the internal magnetic pitch angle, which can then be used to infer the distribution of current in the MAST-U tokamak. I will be based mostly at the Culham Centre for Fusion Energy (CCFE).

Further development of the project could include designing a scheme for real-time control of the safety factor (q-profile) of the magnetic field using the MSE diagnostic."

Benjamin Fisher

I completed both my BSc in Physics with Philosophy and my MSc in Fusion Energy at the University of York. It was during my BSc Project where I investigated strike point sweeping that my passion for fusion began and this passion was solidified during my MSc. I will be starting a PhD project at the York Plasma Institute entitled “XFEL Studies for laser fusions: generating data-rich information sets for code benchmarking and validation” and supervised by Prof Nigel Woolsey.

My research will focus on using intense X-ray flashes from XFEL (X-ray Free Electron Laser) and laser-plasma facilities as high accuracy X-ray imagers for laser driven experiments. The aim is to use these measurements and learn how early-time high power laser target interactions and material response seed hydrodynamic instabilities such as the Rayleigh-Taylor instabilities. These instabilities are of significant interest and problematic to the inertial confinement approach to fusion. They are partly responsible for driving asymmetric implosions and the potential to break up an inertial fusion fuel capsule. Through developing new techniques that enable accurate imaging of the seeds of these instabilities we aim to improve the laser-driven inertial fusion implosions.

Calum Freeman

While I was studying for my integrated masters in computational physics at Edinburgh university, a friend commented that as physicists we could contribute to the development of fusion energy. As a result, I'm doing a PhD.

In the summer between my 3rd and 4th years at Edinburgh, I had a fantastic time doing an internship at the Diamond Light Source. While there I was exposed to X-ray imaging (not literally), although it wasn't the focus of my project. Then, between my 4th and 5th years, I attended the CCFE Plasma Physics Summer School.

My Senior honours project looked at lithium/sodium superconducting at high pressure, and my masters project was focused on thin layer turbulence.

My current project's title is "Transformational imaging diagnostics for inertial confinement fusion". Inertial confinement fusion involves heating and compressing a small amount of fuel (deuterium and tritium) with lasers until it is dense and hot enough to undergo fusion. The lasers cause the compression by ablating a surface material, which leads to "the rocket effect". As the material ablates off the surface, it causes a compression force (through Newton’s laws), using the same idea that explains rocket propulsion.

The maximum density and heat in the core is achieved with symmetric compression, which requires symmetric ablation, which is quite difficult to achieve. This task is made especially difficult as it is hard to image inside the fuel.

Under the supervision of Nigel Woolsey (University of York) and Robbie Scott (STFC-CLF), my project's goal is to develop new imaging techniques (likely involving phase contrast imaging), to aid and improve inertial confinement fusion diagnostics. This will likely involve using computational simulations to test the imaging technique to see if it yields accurate images and useful results.

G

Paul Gellersen

I am a Fusion CDT student supervised by Chris Murphy, and my research is on the use of laser wakefield accelerators as x-ray sources, which may have applications in inertial confinement fusion.

My undergraduate degree was in Chemistry at Oxford University, which I completed in 2023. The 4th year of the degree was dedicated entirely to a research project, for which I worked on development of a laser-induced desorption source for photo-induced reaction dynamics experiments. I found I really enjoyed research and the academic environment, and this inspired me to apply for PhDs. In particular I discovered a passion for experimental physics, which, along with a longstanding interest in fusion energy, led to me choosing the Fusion CDT.

In a laser wakefield accelerator a high intensity laser pulse generates a plasma wave as it propagates through a gas. Electrons can enter this plasma wave and be accelerated rapidly in the wake of the laser.  Under the right conditions, these electrons can also oscillate and so produce synchrotron radiation in the x-ray region. The challenge I will be taking on is to optimise wakefield accelerators for generation of these x-rays, and thus create an x-ray 'laser'. It is already possible to generate high power x-ray laser pulses using x-ray free electron lasers (XFELs), but these require several kilometres of undulators, whereas laser wakefield accelerators may be able to generate the same laser powers over a few metres.

 Theo Gheorghiu

I completed my MEng at Imperial College London in 2020, presenting my thesis concerning the investigation of a set of possible perturbation sources in inertial confinement fusion capsules, based on recent observed phenomena named ‘meteors’ which are associated with degraded performance.

I have moved into MCF on the basis that it seems more feasible to extract usable energy than in ICF - a key issue for the future of fusion. Needless to say, success guarantees the energy needs of humanity for millennia, and would provide an energy dense power source ideal for expansion into the solar system at the very least. 

The project, “Numerical Investigation of Plasma Turbulence and Filament Dynamics in Three-Dimensional Tokamak Geometries” will be supervised by Dr. Benjamin Dudson of York, and Professor Fulvio Militello of CCFE - this will involve investigating plasma characteristics and field structures in the SOL and near the divertor, which is very relevant to energy transfer from the fusion plasma, and so is particularly exciting.

  Rowan Ghiam

I have recently graduated from the University of York with a Masters in Physics. During my undergraduate degree I specialised in Plasma Physics, however, my Masters project was engineering based, and involved developing a control moment gyroscope for a motorbike. I also have experience with theoretical work, having completed a summer internship looking at angular momentum generation in nuclear fission. 

My PhD is supervised by Dr. Istvan Cziegler, and will involve looking at the interplay between the plasma edge to scrape-off layer coupling and divertor conditions. Currently, these regions can be modelled individually; however, I hope to gain a deeper insight into each of these in order to contribute to an integrated model of them together.

Daniel Greenhouse

During my undergraduate degree, at the University of Birmingham, I specialised in Particle Physics with a direct focus on simulations of the prospective detection of a Higgs Boson at a future Large Hadron Electron Collider. Compelled by the allure of the vital benefits of Nuclear Fusion, I was keen to become involved in the ongoing incredible research. I transitioned to Plasma Physics research with the help of a UROP project at Imperial College London where I worked on the DiMPl simulation code investigating dust in magnetised plasmas.

I am currently undertaking a PhD, supervised by Prof. Bruce Lipschultz, Dr. Ben Dudson and Dr. James Harrison, in continuing the development of an Integrated Data Analysis (IDA) method. The technique uses a Bayesian framework to combine a multitude of diagnostic measurements of the divertor to aid insight into this critical region of a tokamak. The aim is to apply the IDA technique to real divertor plasmas at MAST-U in order to provide comparison of various divertor configurations. These configurations theoretically offer significant improvement of heat spread at the divertor surface which is a major hurdle that must be overcome by a future Nuclear Fusion power plant.

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  Chris Herdman

I completed an MPhys as an undergraduate at York, with a project using a hybrid code to model electron transport in a structured target design for laser-plasma interactions. Now, I’m back at York for a PhD project in the same vein, again supervised by Dr Kate Lancaster.
The project is titled “hot dense matter creation via ultra-intense laser interaction with novel structured targets”. High-power lasers can achieve intensities high enough to generate relativistic electron beams from small targets, and by structuring these targets, the efficiency of the interaction can be improved and the resulting electron beam controlled. This is of particular importance for the fast ignition regime in inertial confinement fusion. I’ll pursue this using both computation and
experiment.

Matthew Hill

Prior to beginning my PhD here at York, I studied my MPhys at York and completed my MPhys project in the YPI, supervised by Dr István Cziegler. The project involved comparing particle image velocimetry algorithms created by PhD students at the YPI for turbulence in magnetically-confined fusion plasmas.
My PhD project, however, is in the Low-Temperature Plasmas research group of the YPI. It is titled ‘Plasma-Enhanced Pulsed Laser Deposition of thin films for photoelectrochemical water splitting to enable a hydrogen economy,’ and is supervised by Dr Erik Wagenaars.
Thin films have many applications in modern technology, including photocatalysts that use solar energy to dissociate water molecules to produce hydrogen fuel. Metal oxides are widely-accepted materials for photocatalytic thin films. Plasma-Enhanced Pulsed Laser Deposition is a novel method for producing such thin films, and is built upon the well-established Pulsed Laser Deposition (PLD) method. In PE-PLD, material from a metal target is ablated into a plasma plume using a high-powered pulsed laser inside a vacuum chamber. This material interacts with an RF-generated nonmetal plasma within the chamber and is subsequently deposited onto a substrate as a thin film. PE-PLD remains an active area of research, and the overarching goal of my project is to develop a deeper understanding of the underlying plasma physics and chemistry of thin film deposition via PE-PLD.

Thomas Hipgrave

I graduated from an integrated masters degree in physics with astrophysics from the university of York in 2022. During my undergraduate degree, I specialised in plasma physics and fusion energy, a subject I found deeply interesting due to its challenging concepts and potential applications. My masters project focused on understanding the characteristics and requirements of different forms of ignition in Inertial Confinement Fusion (one of the two main approaches to fusion power production). 

My PhD is supervised by Dr John Pasley, who also supervised my masters degree, and is titled “Advanced Inertial Confinement Fusion Schemes”. This is a very open ended project with a wide variety of potential avenues to explore. Currently, my focus is on extending my previous work on ignition.

 Caleb Hopkins

My background is an integrated Masters in Physics with Astrophysics completed at the University of York. I had chosen York for my undergraduate for its research into plasma physics and fusion energy, a topic I had been passionate about for a long time. This led to me completing my Master's thesis studying a so-called traffic-jam hydrodynamic instability occurring in plasmas, and then to applying for a PhD project with the Fusion CDT.

For my project, I will be working on microwave current drive and heating in MAST-U.

Microwave heating of a tokamak plasma has the advantage of being able to position the sensitive components far away from the reactor, preventing damage due to neutron bombardment. They can also be used to drive current in the plasma for the generation of the poloidal magnetic field, removing the need for a large central column.

MAST-U has recently been equipped with gyrotrons capable of producing microwaves that could be used to heat and drive a current in the plasma. My project will revolve around designing experiments to determine the best way to implement these gyrotrons to achieve this, by comparing the results of multiple models to diagnostic data from MAST-U.

 Lena Howlett

I graduated with an MPhys degree from the University of Manchester in 2017 and came straight to York to complete the MSc in Fusion Energy at the York Plasma Institute. Now I am starting on the Fusion CDT with a project titled "Turbulence in confinement transitions in novel divertor configurations" supervised by Dr Istvan Cziegler at York and Dr Simon Freethy at CCFE.

The high-confinement regime or H-mode describes a state of greatly increased performance, with increases in plasma density and temperature leading to a significant gain in fusion power. Since the dominant source of transport of mass and heat between the magnetic flux surfaces is due to turbulence, the increase in confinement for the transition from low-confinement L-mode to H-mode can be thought of as a suppression of turbulence.

The confinement regimes are influenced by macroscopic parameters such as the geometry of the divertor (the exhaust of the tokamak), and the recent upgrade of the Mega-Ampere Spherical Tokamak (MAST-U) will allow a detailed study of the effect of different divertor configurations on the L-H transition, including advanced concepts such as the super-X divertor which have not previously been explored. In my project I will be analysing data from imaging diagnostics at MAST-U with the aim to examining the nonlinear dynamics of phase transitions.

Emma Hume

Having studied for my MPhys at York and completing my Masters project within YPI, I am now continuing my studies at York as part of the Fusion CDT programme. My project is titled "Hot, dense matter creation via ultra-intense laser interaction with novel, structured targets" and is supervised by Dr Kate Lancaster.

Inertial confinement fusion uses intense lasers to compress and heat a fuel pellet and create energy. A variation of ICF, called fast ignition, uses electrons produced during ultra-intense laser interaction with matter to heat the fuel to fusion temperatures. We can increase the efficiency of this process by collimating the electrons or increasing the amount of laser energy absorbed. At present the absorption is limited by the density the laser can penetrate to, but there are options to improve this. One way is to use nano-structured targets such that absorption of laser energy is increased to create hotter material. The project aims to investigate this method through both experimental and simulation work to gain a higher understanding of the physics of heating matter for fusion and improve hot, dense matter creation. This work will not only have use in ICF but can also be applied to nuclear astrophysics, radiation transfer and the studies of hot dense matter properties.

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Christina Ingleby

I have recently graduated from the University of Kent with an MPhys in Physics with Astrophysics. While completing my undergraduate studies, I became increasingly more interested in Plasma Physics and its real-world applications, particularly in Fusion Energy.
The project I will undertake at York is entitled ‘Astrophysically-relevant QED plasmas in the laboratory’, supervised by Dr Kate Lancaster and Dr Chris Ridgers. The project focuses on creating quantum electrodynamic (QED) plasmas using new multi-PW lasers. This increase in laser intensity will allow for new light-matter interactions to be observed, mainly considering cases where electromagnetic fields are so strong that QED plasmas are created. The plasmas are governed by ultra-relativistic plasma processes that alter the behaviour of the plasma entirely; we move away from classical processes and toward quantum effects. There is minimal experimental work undertaken in this area, so QED plasmas are relatively unexplored experimentally. There are a variety of applications of QED plasmas including as a source of gamma rays for radiography of fusion materials. The project will be a combination of laboratory and experimental work, and simulations to explore this new plasma regime. 

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K

 Max Kellermann-Stunt

Before joining the university of York, I completed my MSc at Imperial College London. My research project involved developing in house deformable mirrors for laser beam correction for the Cerberus and Chimera laser systems. 

My PhD research will combine experiments and simulations on a non-equilibrium hydrogen plasma, where electrons are relatively energetic compared to ions and neutrals, investigating their dynamics and chemical kinetics when seed gases are admixed, and investigate strategies for enhancing their control within this challenging regime. The results of this project will feed into the development of fusion science and technology via our improved understanding of non-equilibrium plasma physics relevant to the divertor. The findings are also applicable to distinct non-equilibrium plasma applications including, for example, nanoscale materials processing and satellite propulsion.

Mike Kryjak

Following the completion of my MEng in Mechanical Engineering at Brunel University, I spent five years as a combustion computational fluid dynamics specialist in the energy industry. I have joined the CDT to fulfil my long-standing dream of switching to nuclear fusion and to contribute towards its future commercialisation.

My project is titled "Modelling Kinetic Effects on the Heat Exhaust in High Power Tokamaks" and will be supervised by Dr Chris Ridgers and Dr Ben Dudson based in York. It concerns the simulations of the plasma edge - a region where the plasma exhaust is directed towards the divertor by the tokamak's magnetic fields. In more powerful reactors, this can expose the divertor to heat fluxes beyond what known materials can withstand. Minimising the heat loading to manageable levels poses several yet-unsolved challenges, and is key to ensuring performance in high power output reactors such as ITER, DEMO and STEP.

Current state-of-the-art models of the plasma edge assume local thermodynamic equilibrium (LTE). This project will challenge this assumption by using new, pioneering non-LTE models, which have shown significant departures from previous results obtained for ITER. This work will explore the impact of using this new approach on furthering our understanding of plasma exhaust and divertor phenomena, with a focus on assessing strategies for mitigating divertor heat loading.

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Owen Lawrence

The emphasis York placed on plasma physics was a key factor in my decision to study here. It is where I obtained my MPhys, in a project that utilised gyrokinetic simulations to study the growth of microinstabilities in spherical tokamaks. This further fueled my fascination with plasma physics and led me to continue my studies at York on the CDT.

I am now redirecting my understanding of plasmas toward laser-plasma interactions, specifically the generation processes of X-rays during laser wakefield acceleration. Wakefield acceleration involves using the oscillating electric field of a laser to induce displacement of electrons in a plasma and create zones of positive and negative change. The change difference can then be harnessed to accelerate electrons to extremely high velocities and produce X-rays through several processes. 

This research has the potential to compact particle accelerators to a fraction of the size, replace the current method of X-ray generation for medical purposes, increase our understanding of difficult to study astrophysical phenomena and of course contribute to the development of inertial confinement fusion.

 Sidney Leigh

I completed my Masters in Physics with Astrophysics at the University of York on a computational modelling project with the York Plasma Institute. My project at the CDT will look at performance-limiting plasma instabilities in the ITER tokamak, building upon a theory and computational model recently developed at York.

In particular, the work will focus on an instability known as the neoclassical tearing mode (NTM), a mechanism that leads to the formation of ‘magnetic islands’ where heat and particles can escape confinement. While smaller islands dissipate over time, the unmitigated growth of larger islands would lead to significant losses in confinement and heating power, or potentially a catastrophic disruption. Testing the NTM theory against experimental measurements of tokamaks may provide solutions to controlling the formation of islands in newer, much larger reactors such as ITER.

Nicola Lonigro

I studied for both my undergraduate and master degrees in Physics at the University of Padua, in Italy. My interest in nuclear fusion started during my bachelor thesis research on developing a convolutional neural network for the analysis of infrared imaging system data on the SPIDER experiment. It then continued during my masters degree through elective courses and it culminated in my masters thesis on the study of parametric decay instabilities during Electron Cyclotron Resonance (ECR) heating on the NORTH tokamak at the Technical University of Denmark.

My Ph.D project, supervised by Professor Bruce Lipschultz and Professor Kieran Gibson at the University of York and Dr James Harrison at CCFE, involves the study of the divertor region of the MAST-U tokamak through the new Multi-Wavelength-Imaging (MWI) diagnostic.

This diagnostic allows researchers to acquire eleven video movies corresponding to 2D brightness images of the divertor region, each filtered for a different wavelength. The profiles have different dependencies on the plasma parameters and by putting them together with the data from the other diagnostics, these parameters can be reconstructed. The MWI data will be integrated in the Bayesian framework currently being used to determine the divertor state, thereby improving its capability.

Handling the large exhaust heat loads corresponding to that of a reactor is one of the main problems on the way to commercial fusion tokamaks providing a net power source. The magnetic topology of the divertor (where the exhaust power is carried towards surfaces) in MAST-U is flexible and the MWI diagnostic will help in determining the most appropriate divertor configuration to optimize the dissipation of power and thus reduce peak power loads.

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Ryan Magee

I completed my BSc in Physics at the University of Surrey, undertaking a placement year in the ion-beam research group at Applied Materials, USA. My dissertation investigated implant induced defects in silicon carbide and the resultant changes to its material properties.

My PhD research at York focuses on the development of low-temperature plasma ion sources, which are of significant interest for applications ranging from neutral-beam injection for magnetic confined fusion, electric propulsion and advanced manufacturing. We are particularly interested in the physics of negative ion production in these sources, and will investigate this via a combination of 2D fluid-kinetic simulations and non-invasive optical diagnostics.

 Felicity Maiden

My background is an integrated masters in Natural Sciences specialising in Physics at the University of York, graduating in 2021. During my degree I was fortunate enough to complete a summer internship working on microwave current drive for STEP which triggered my interest in plasma physics and passion for bringing fusion energy to the National Grid. My masters project was also in plasma physics, looking at how we can model the effect of drifts in the divertor of high power tokamaks.

 For my project on the Fusion CDT, I am back to working on microwave current drive, particularly the use of Electron Bernstein Waves during start-up for prototype spherical tokamaks.

 In order to confine a plasma inside a tokamak, we need to generate a current through the plasma itself. So far, this has been done through induction using a solenoid down the centre of the device. However, there are disadvantages in this approach if we are designing a spherical tokamak power plant. This includes that there is not very much space in the centre column and that we want to be operating the power plant for substantial amounts of time. Microwave current drive offers a solution to both of these problems as the gyrotrons can be located a long way away from the device and can be used for long periods of time. Therefore, it would be ideal if we could design a system to drive the plasma current throughout both phases of operation: start-up (when the plasma is being formed) and steady-state (the main phase of operation, when energy is generated). Microwave current drive in steady-state has been studied extensively but start-up is less well understood.

Therefore, my project will aim to find a microwave system for the start-up phase of the plasma. It is a collaboration between the University of York, CCFE and Tokamak Energy and I will be working under the supervision of Roddy Vann, Simon Freethy, Vladimir Shevchenko and Erasmus du Toit.

Lexi Masters

I graduated from Warwick University in Maths and Physics in 2021, where I acquired an interest in fluid dynamics and, subsequently, plasma physics.  I am particularly interested in turbulence and the difficulties associated with its precise definition and modelling.  My undergraduate project involved investigating transitions from turbulent to laminar states in the plasma interchange model.  My interest in plasma physics led me to study Fusion Energy for my MSc at University of York in 2022-23 and my final project there involved applying uncertainty quantification to the parameter space of a plasma filament model to investigate particle transport through tokamak scrape-off layers.  Fusion represents an opportunity to simultaneously engage in my areas of academic interest and contribute to the development of a technology with the potential to actively benefit our society.

My research will be based at CCFE, supervised by David Dickinson from University of York and Ben Chapman-Oplopoiou from UKAEA.  The aim of the project is to understand the turbulent transport of heat and particles through the pedestal region of spherical tokamaks by using the GENE gyrokinetic code.  Data from MAST and MAST-U indicates that turbulence in the pedestal region is primarily driven by certain electromagnetic microinstabilities which we hope to compare using GENE and thereby characterise the dominant transport mechanisms.  Once we have an understanding of how different instabilities affect pedestal transport, we aim to apply these findings to make transport predictions for future STEP pedestals.

 Hasan Muhammed

I am an Imperial College London physics graduate who is moving onto the CDT after finishing the wonderful Fusion MSc at York. My motivation lies in the prospect of creating a tokamak plasma capable of generating clean and near limitless power. To this end, I will be working on simulations of ‘Turbulence and Instabilities in the Super-X Divertor’ under the supervision of Dr Ben Dudson.

The divertor is used to extract heat and ash produced by the fusion reaction, minimise plasma contamination, and protect the surrounding walls from thermal and neutronic loads. It is a vital component in any modern tokamak design, but improved control and understanding of the divertor plasma is still required before a viable fusion power plant can be created. Optimisation of the divertor requires enhancement of cross-field transport (through turbulence), as well as to the removal of energy and momentum from the plasma using atoms, molecules and impurity ions.

My work aims to generate a better understanding of the toll that turbulence and instabilities have on the removal of energy and momentum from divertor plasmas. I will use state of the art simulation tools built on the BOUT++ framework and aim to make improvements to the underlying mathematical and physical models, and the implementation of numerical algorithms. I will then look to using these models to understand experimental data and make predictions which can be tested experimentally on the upcoming UK flagship tokamak experiment, MAST-Upgrade. One of the key features of this tokamak is the Super-X Divertor that implements a long-legged divertor configuration with a more complex magnetic topology

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 Charlie Nicholls

I completed my undergraduate degree in physics at the University of York and presented my masters thesis on the properties of a type of small scale tearing parity instability observed in gyrokinetic simulations. These look similar to the well understood micro-tearing modes but are driven by a different mechanism.

My PhD is looking at gyrokinetic simulations of electromagnetic instabilities in high beta tokamaks, also at York and supervised by Dr David Dickinson and Professor Howard Wilson.

 Ann-Marie Norton

I’m a recent graduate from the University of York with an MPhys in Physics with Astrophysics; I’m excited to be starting my PhD at the University of York.

My project will look at different materials responses to high power dynamic compression and includes experimental work using the European XFEL facility. XFEL produces a laser-like pulsed X-ray beam that will be used on the femtosecond timescale to reveal how the material deforms under high pressures and temperatures. Real-time probing of the material will be carried out using X-ray diffraction. This work can also shed light on the early stages of compression that occurs in ICF capsules. Dr Andy Higginbotham supervises my project.

 Arun Nutter

During the final year of my MPhys at the University of Warwick, I found myself drawn to the field of plasma physics and fusion energy. My CDT project concerns inertial confinement fusion and is titled “the polar direct drive shock ignition approach”. It will be supervised by Professor Nigel Woolsey at York and Dr Robbie Scott at the Central Laser Facility.

The National Ignition Facility is currently set up to run indirect drive experiments, where lasers are focused on a hohlraum, a shell encasing the fuel capsule, which radiates x-rays onto the capsule to trigger an implosion. In direct drive fusion, the lasers strike the capsule directly, hopefully increasing the process’ efficiency as no energy is expended in heating the hohlraum. However, with this comes a whole host of new problems, such as those associated with the overlapping of multiple coherent laser beams.

I intend to study these problems holding back ICF by using advanced radiation hydrodynamic models to study implosions, and new computational techniques to address the complex physics associated with laser-plasma interaction and the effect of overlapping many laser beams, as well as working on current sub-ignition scale experiments with the OMEGA laser.

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 Michel Osca Engelbrecht

 Nick Osborne

After completing the Fusion Energy MSc at York University part-time, I am now starting on the CDT programme (also part-time).

Before my MSc, I was away from studying physics for quite some time, working as a physics teacher among other things.  It is a privilege to return to my own studies and make a contribution within the fusion project!

My project supervisors are Dr Mark Bowden at the University of Liverpool and Dr Kevin Verhaugh at the Culham Centre for Fusion Energy (CCFE).

In future tokamak devices. handling the very intense energy flowing out of the plasma to the divertor is going to be an important issue.  Operating the plasma in a mode called detachment is a key part of the solution but the conditions for detachment are not yet fully understood.  This is an experimental project looking at plasma molecule interactions in the divertor of MAST-U (a spherical tokamak at CCFE) with the objective of determining their influence on detachment.

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Ben Pritchard

Before joining the Fusion CDT, I completed an MEng degree in Mechanical Engineering from University of Leeds and had worked in the motor racing industry for 2 years. My PhD topic will focus on a microwave imaging device known as SAMI (Synthetic Aperture Microwave Imaging). SAMI is an excellent device that showcases the diversity in disciplines (from physicists to electrical engineers) required to achieve sustainable fusion energy production.

I will be working on creating a second generation SAMI device that will be able to image fusion plasma behaviour that has never before been captured. The device will allow hypotheses to be tested and will provide a new diagnostic technique for scientists to use in the current and next generation of fusion machines.

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Marcus Quantrill

I recently completed the MSc in Fusion Energy at the University of York after working for a technology consultancy in Cambridge for over two years. I have a BSc in Theoretical Physics from Imperial College London, having graduated in 2018. I am now beginning a PhD at the University of York.

My project is titled "Non-linear modelling of performance limiting MHD and disruptions in spherical tokamaks". I will be studying important instabilities -- such as neoclassical tearing modes (NTMs) -- that may lead to disruption events in spherical tokamaks such as MAST-U and the upcoming STEP reactor. Disruption mitigation is important to avoid damaging critical components in a tokamak, such as the first wall and the toroidal field coils.

The project will involve analysing data from MAST-U to understand how NTMs lead to disruptions. I will be extending existing computational models to account for the spherical geometry in MAST-U and compare their output to experimental data. I will also be exploring existing theoretical models which explain the role of NTMs in disruptions. The output of the project will inform strategies to mitigate disruptions in future MAST-U operations and has the potential to aid with the design for STEP.

My supervisors are Professor Jonathan Graves and Dr. Christopher Ham.

Leo Richardson

I am a PhD Fusion CDT student studying with the University of York in collaboration with CCFE. My project is titled Electromagnetic Turbulence and Advanced Transport Modelling and is under the supervision of Dr David Dickinson and Dr Colin Roach.

The project focuses on studying and modelling electromagnetic plasma instabilities and the associated turbulence. By understanding these fluctuations and improving upon the numerical models used to simulate them we can better understand what is needed for improved confinement and thus optimised tokamak performance.

I graduated from the University of York with a Master of Physics, with my final year project being titled Space Tether Systems for Space Junk Removal. I was motivated to pursue fusion research due to my strong beliefs of the many advantages that fusion energy offers humankind.

Sebastian Ruiz-Gonzalez

As an undergraduate, I did a BSc in physics at the Universidad Autónoma Metropolitana in Mexico City, specializing in plasma physics. I then did a year in Paris studying a master’s in physics focused on simulating magnetically confined plasmas. Through my early years, I became fascinated with the idea of fusion energy. Now, I am proudly starting a PhD, researching “Flexible Grids For Complex Tokamak Topologies” with Dr. Peter Hill.

Magnetically confined fusion devices called tokamaks are one of the most promising devices to achieve commercial fusion. Their exhaust systems, called divertors, are of particular importance as the complex physics in that region sets the boundary conditions "upstream" for the fusion-producing core, and so ultimately the power production. Advanced divertor designs, such as the "super-X" and "snowflake" divertors can have complex magnetic geometries and topologies which can make simulating them a challenging task.

The project's objective is to adapt and extend the world-leading open-source BOUT++ framework to better handle advanced divertor designs by developing and testing a new mesh implementation in C++. The new mesh will then be used to study the effect of the shape of these advanced designs on the upstream conditions and compare simulations to experimental results from the UK's MAST-U tokamak.

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 Celine Schauman

I completed my MSci in Physics With a Year Abroad at Imperial College London in 2020 and have long been interested in nuclear fusion. My desire to pursue an academic career in the field only solidified after I wrote my masters thesis on the topic of magnetohydrodynamic instabilities in tokamaks. I will be starting a PhD project at the York Plasma Institute entitled “Exotic Plasma Instabilities in Strongly Rotating Tokamak Plasma” and supervised by Howard Wilson (University of York) and Jonathan Graves (EPFL, Lausanne).

Neutral beam injection, commonly used for heating tokamak plasmas, imparts momentum to the plasma. In this way it can drive significant plasma rotation in tokamaks like MAST-U, at which point centrifugal and Coriolis effects become important. These can affect the behaviour of plasma instabilities and even introduce new ones. Because future tokamaks like STEP and ITER will experience very little rotational flow it is important to study now how it can impact plasma dynamics and stability. 

My project will focus on studying rotation-driven Kelvin Helmholtz-like instabilities using a combination of analytical methods and computational modelling. In particular, the goal is to identify the conditions for which these instabilities occur and develop a computational model which may be extended to future tokamaks.

 Tobias Schuett

I completed my undergraduate degree in Physics at the University of Münster during which I spent the final year at the University of York and worked on the detection and analysis of edge localised modes in tokamak plasmas. Being convinced of the importance of fusion research, I am now joining the Fusion CDT to study turbulence in confinement transitions for different divertor configurations. My project will be supervised by Dr Istvan Cziegler (YPI) and by Dr Simon Freethy (CCFE).

After the plasma in a tokamak is heated beyond a critical power threshold, the turbulence located at the edge of the plasma is greatly suppressed and a transition from what is known as low confinement mode (L-mode) into high confinement mode (H-mode) takes place. While the L-H-transition power threshold dependency on macroscopic plasma parameters such as density and temperature is well understood, the suppression of turbulence also shows to be influenced by different divertor geometries. This coupling is not fully understood and a physical picture is yet missing.
The divertor, which can be thought of as the exhaust of the tokamak, will be subject to especially high heat fluxes in future magnetic confinement fusion devices such as ITER. Different divertor geometries can reduce the heat flux by spreading the magnetic field lines and are hence a promising solution to this problem. I will be conducting research on the MAST-U experimental spherical tokamak that enables the investigation of novel divertor geometries such as ‘Super-X’ and their influence on the turbulence dynamics.

 Deborah Selemon

My interest in nuclear fusion began when an undergraduate internship in Nigeria directly exposed me to the negative impact of burning fossil fuels for electricity generation. Following this experience, I pursued a Masters degree with the Erasmus Mundus Joint Masters Degree program in nuclear physics, focusing on fusion in my thesis. For my MSc thesis, I studied the feasibility of using machine learning techniques to study charge exchange spectra from the ASDEX Upgrade tokamak in Germany. I am thrilled to be continuing fusion training and research with the Fusion-CDT program.
For my PhD, I will be under the supervision of Roddy Vann and David Dickinson to characterize turbulence at the plasma edge using microwaves. Turbulence is the dominant mechanism for the loss of heat from tokamaks and understanding it is critical to successful operation of a tokamak reactor.

Injected microwaves at sufficiently low frequency bounce off the plasma edge at a density related to the wave frequency. It is proposed that comparing the polarisation of the back-scattered microwaves to the polarisation of the injected beam can be used to determine the extent to which the scattering turbulence is electromagnetic or electrostatic – thereby discriminating between two different models for edge turbulence. My project will use existing high performance computing codes to study the feasibility of this approach; the computational models will then be validated with experiment by using the Synthetic Aperture Microwave Imaging (SAMI) diagnostic at MAST-U.

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 Kitt Thomas

I have recently completed an MPhys Physics degree at the University of Manchester, studying chaotic Arnold-Beltrami-Childress magnetic fields in plasma using numerical simulations in my final year. I am now beginning a PhD at the University of York.

My project is titled ‘Probing the plasma pressure limit in tokamaks’, and focuses on the plasma instabilities known as neoclassical tearing modes (NTM). These instabilities can produce current filaments within tokamak plasmas, leading to the formation of ‘islands’ within the magnetic field, which can be detrimental to plasma confinement within fusion reactors. A key effect of NTMs is also a significant reduction in plasma pressure, resulting in reduced fusion power. Seeking to understand NTMs is therefore crucial to the efficient operation of modern fusion reactors such as MAST-U, and future reactors such as ITER.

The project will largely involve the development of a model and simulation code that predicts a ‘critical’ island width above which NTMs continue to grow, and testing this code against experimental measurements on MAST-U.

 Mark Turner

I have recently completed the MSc in fusion energy at York and after a long break from physics it was great to stretch my brain to learn plasma physics and in particular laser plasma physics. I discovered a great research community in the york plasma institute and had the privilege to do my masters thesis under Professor Chris Ridgers simulating laser stimulated magnetic fields in gas jets.

Now as part of the Fusion CDT I will be working with Dr Chris Murphy on ICF relevant laser plasma interactions with exotic pulses. These exotic pulses are shaped to give orbital angular momentum to the wavefront which opens rich opportunities to study their effect on laser plasma instabilities and X-ray production from Laser-Wakefield electron acceleration. I will be using state of the art simulation tech simulation techniques alongside experiments at international laser facilities in order to better understand the potential benefits of these exotic pulses.

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 Joseph Umpleby-Thorp

“I studied Natural Sciences concentrating on Physics and Chemistry at the University of Durham. I then completed the MSc in Fusion Energy at the University of York, realising a project studying the tensile properties of tungsten containing helium bubbles using molecular dynamics simulations.

Now starting the CDT, I will be supervised by Dr Andy Higginbotham. My project will be based on using machine learning techniques to analyse x-ray diffraction patterns produced from the responses of a variety of materials to high power dynamic compression. The experimental data will be produced using the European XFEL facility. The facility produces laser-like X-ray beams on the femtosecond timescale. These energetic pulses are used to reveal how materials deform at very high pressures and temperatures. Using machine learning we aim quickly analyse the results of these experiments, this will hopefully guide the experiments to more fruitful parameters and regimes, detecting patterns that would otherwise be missed. These experiments can be used to reveal the characteristics of early compression stages of ICF capsules.”

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 Yuyao Wang

I obtained my BSc degree in Physics from the University of Bath in 2017 and graduated from the University of St. Andrews with an MSc Degree in Astrophysics in 2018. 

I then spent the next three years working as an innovative solution engineer in the connected and autonomous mobility industry. To satisfy my growing interest in astrophysics, fusion technology and plasma physics, I decided to pursue a PhD at Fusion CDT.

I have now started my PhD at the University of York under the supervision of Professor Nigel Woolsey. My research focuses on understanding the fundamental physics behind hydrodynamic instabilities, turbulence and material mix as manifest in the matter at extreme conditions. These physical behaviours are observed and studied at enormously different scales extending from the implosion of a millimetre-sized inertial fusion fuel capsule to the explosion of a massive star.

As part of my PhD project, we are currently collaborating with First Light Fusion Ltd. to design and perform an experiment to replicate supernova shock-cloud interactions in a laboratory scale by using their light gas gun facility. There are opportunities to propose similar ideas that use high energy laser in the UK and elsewhere. My studies aim to contribute to understanding the physics behind high energy density astrophysical and laboratory phenomena as well as developing reliable tools and techniques for measurements relevant to inertial confinement fusion.

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