‘The pathway to commercial fusion is the adventure which drives us all’ – Howard Wilson on his return to Culham

CCFE 05/03/2018

Professor Howard Wilson returned to Culham as Programme Director at the start of October. He spoke to us about what has changed since he worked here previously, and his hopes for research towards the first demonstration fusion reactors. As well as his CCFE role, Howard is Chair at the University of York as Director of the York Plasma Institute and the EPSRC Fusion Centre for Doctoral Training.

“It’s essential we find a solution to the energy problem and it’s hard not to be enthusiastic about that working back here at Culham,” Howard Wilson stated. “But what is fantastic is that nuclear fusion research is much more of a national programme than it was when I left back in 2005. Back then Culham had relatively few collaborations with UK universities. Now we see many different link ups with a wider range of universities, increasingly integrated into the national programme.”

Howard, a leading theoretical plasma physicist, returned to Culham in October 2017. The place itself hasn’t changed drastically whilst he has been away, but what is different is the wider appreciation of the vital work done at Culham.

Having left to establish an academic fusion energy research and training programme that grew into the York Plasma Institute at the University of York, he has now returned part-time and is seeking to combine both roles to encourage wider involvement in fusion energy, and working towards its successful commercialisation.

Perception of fusion is good – but we must keep up the good work

“Public perception of fusion is generally good, and rightly so, but it is vitally important that we maintain this by effective communication about our progress and the importance of world class research and development to address the remaining challenges.

“Other sustainable energy technologies can demonstrate progress through steadily increasing the fraction of power they deliver onto the grid as advances are made. Although this fraction is still relatively small, it is measureable progress that is clear to all.

“The situation for fusion is different – we have to achieve certain conditions to generate any fusion power which, we expect, will then be abundant. In the meantime, our achievements are measured in terms of proximity to these conditions, and even though there has been great progress, this can be difficult to quantify and explain to those outside the field.“

Howard first joined Culham’s theory department in 1988 as a research scientist. Having completed his PhD in particle physics at Cambridge, his first stint here involved him developing theories of plasma instabilities, including the so-called “peeling-ballooning” model for ELMs (Edge Localised Modes). He co-led (in collaboration with General Atomics in the US) on the development of the ELITE code (Edge Localised Instabilities in Tokamak Experiments) to provide quantitative predictions of the plasma stability in the insulating layer – called “the pedestal”. This code is now used for analysing the pedestal stability to understand how and when the ELM is triggered on tokamaks worldwide.

He also led the development of the plasma physics basis for compact fusion reactor designs based on the spherical tokamak, including an electricity-producing power plant and a small reactor for components testing.

Student world increasingly engaged with fusion

It was his passion for enabling future generations to be informed about nuclear fusion that led to him taking up his post at the University of York 13 years ago.

“At the time UK fusion research was predominantly done at Culham, and university research programmes were limited to a few excellent individuals around the country. The University of York was seeking to expand its plasma physics group and I saw the opportunity to establish a fusion plasma physics programme there.

“For me, it’s important that young people are aware of the opportunities that fusion research offers, and also gain a knowledge of what fusion research is about – knowledge that they will carry through whatever career path they choose. One way to ensure this is obviously to be involved in the education of those people, and to get fusion further embedded in some of the undergraduate and postgraduate programmes.

“Seeing first-hand how enthusiastic students are about this is extremely fulfilling. It is my privilege to lead the Fusion Centre for Doctoral Training, which has over 60 PhD students at any time. Half stay in the field after qualifying, and half choose careers elsewhere. It’s vital there are people with an understanding of fusion in all sectors, whether that be politics, media or other research fields.”

He added: “I hope that (and expect) the 50 per cent who follow other careers can be just as important to fusion as those who stay directly in the field – it is stimulating to see the range of careers that a fusion education prepares our students for.”

The current stats at York are certainly impressive. As many as 60 undergraduates choose the final year Plasma Physics and Fusion course. Added to this are another 20 students undertaking the York Masters in fusion energy and a further 15 PhD students in each year group. “Of course this isn’t all down to me,” Howard said. “It is the team of academic and support staff at York and our partner universities which ensure that it works so well.”

“Coming back, one sees the evolution of the programme here at Culham in terms of technology, materials science, plasma physics, and engineering. There is strength in all of these, but the real power of the programme will come from an integration of these capabilities.”

Fusion of the future

“One of the areas that most excites me is to bring the combined strengths of Culham across these disciplines to look for a more compact route to fusion power. Perhaps even a smaller demonstration fusion reactor than is currently being considered.

“You see, at the moment the DEMO design is broadly based on a scaled-up version of the ITER project, so it is a fairly big beast with a high capital cost. The spherical tokamak, such as the newly-built MAST Upgrade experiment at CCFE, offers the potential for a more compact route to fusion. However, we cannot know whether this is viable yet because our knowledge of spherical tokamaks is still at a relatively early stage.

“MAST Upgrade is exciting because it will help us achieve the fusion objectives of ITER, as well as providing a possible answer for how to control the exhaust power of DEMO. It may also point the way to a more compact route to DEMO. Add to that the unique capabilities of JET and the eagerly anticipated fusion power experiments with the deuterium-tritium fuel mix and it is easy to see why Culham is one of the most exciting places to do fusion research in the world.

So what does a typical working week look like?

“Firstly, I don’t really have a normal week. In terms of when I am here at Culham, my role is about understanding what the different programmes are doing, and working with the programme teams to decide priorities alongside the European and international fusion programmes, the overall UKAEA and EPSRC strategies and, of course, the Government’s Industrial Strategy.

“Another integral part is to continue to integrate Culham’s programme with the wider academic community, and keeping aware of the mutually beneficial opportunities there as we plan our own programme.

“We are building an exciting vision for UK fusion and the pathway to commercial fusion energy; there are challenges ahead but it is those challenges that stimulate us and the adventure of the journey to fusion power that drives us. It is great to be a part of it.”

What is certain is that Howard is extremely focused and driven, as well as incredibly busy. So how does he switch off when the chance comes?

“I love to cycle and to run, as well as winter hill walking – ideal ways to counter the effects of my passion for a pint or two. I enjoy DIY, and get plenty of practice with our 250 year old house in York and my old Range Rover – but it is probably best if I’m not allowed to approach a tokamak with a spanner in my hand.”