I walk into the facility and my heart lifts. The giant machine is still there as I remembered it. My many hours spent years ago in this laboratory feel so recent. I’d heard that Australia’s nuclear fusion research machine, the H-1 Heliac, had been sold to China, and so had mentally prepared myself to find an empty space where it once sat. But it’s still here, albeit in pieces, as they prepare the multi-million dollar precision instrument for transport halfway around the world.
The lid is off, giving me a chance to do something I never got to do when I was a researcher here: look inside it. Climbing the ladder and peering in, I feel a nerdy excitement at seeing the big electromagnet coils forming a huge twisted torus (donut-shaped ring) inside the circular chamber.
To think that right in front of me hydrogen atoms were heated to millions of degrees, as hot as the sun. Most of us only learn about three states of matter: solid, liquid and gas; but at these temperatures, the hydrogen enters a fourth state, a plasma, where the electrons separate from the atomic nuclei, creating a cloud of charged particles. Too hot to be contained within walls of metal, they need to be confined by a magnetic field within a vacuum chamber.
In machines similar to this one, using isotopes of hydrogen called ‘deuterium’ and ‘tritium’, and with enough heat and magnetic confinement, nuclear fusion can be achieved — the same reaction that’s powering our sun. It’s the ‘holy grail’ of sustainable energy. Unlike nuclear ‘fission’, where uranium atoms are split to release energy, the end-product of nuclear ‘fusion’ is helium, which is benign.
The famous physicist Stephen Hawking, when asked what problem he hoped scientists would solve by the end of the century, answered: ‘Nuclear fusion. It would provide an inexhaustible supply of energy without pollution or global warming.’
But with the H-1 Heliac being sold and soon to be shipped overseas, I’m wondering if this is the end for Australia’s fusion research. I’ve cycled to the Australian National University (ANU) in Canberra, keen to meet with the groups working in this field.
Arriving at the ANU campus earlier, my first stop is the Mathematical Sciences Institute, and I find my way up to the second floor and knock on one of the office doors. I’m welcomed by Associate Professor Matthew Hope, who suggests we stroll over to a nearby cafe together.
Matthew talks like a physicist, throwing around scientific terms that I used to know but have since forgotten. It takes me a while to adjust to the new language, and I often have to interrupt to ask him to explain. We talk about the developments in nuclear fusion research, and reminisce about the old H-1 Heliac machine.
I reflect on my own fusion journey which started fifteen years ago when I spent a summer here as a researcher with the Australian Fusion Research Group. Every day I would follow my familiar walking route across campus from the college I was staying in to the Research School of Physics and Engineering. I was provided a small office there, but I also spent time in the large test laboratory to work on my project.
Back then the big H-1 Heliac took pride of place in the main facility and everyone seemed to be using it for their research. I was in charge of a device called a spectrometer that measured the different frequencies of light being created inside the H-1 Heliac, and from this I’d try to determine what types of particles were in the plasma. As a young undergraduate student I was slightly in awe of my supervisor Professor John Howard, who headed up the group, and always felt nervous around him.
I’d never been part of such an advanced project before. I remember sitting in the control room overlooking the fusion test facility and counting down as the machine prepared to do another pulse. Suddenly the image on all our computer screens would shrink as the high powered electromagnets charged up. The magnetic confinement was only able to sustain the plasma for a fraction of a second (any longer and the extreme temperatures would start melting the walls of the vacuum chamber), but that was long enough to do measurements and get some valuable data.
After the summer was up I went to live in Japan for a year, working as an English teacher in Osaka. Near the end of my time there I heard that the Australian Fusion Research Group was coming to visit Japan’s nuclear fusion test facility. Japan had one of the most advanced nuclear fusion experiments in the world, and I really wanted to see it. I contacted Prof John Howard and asked if I could join them.
A train to Nagoya then a bus that dropped me off on a quiet back road, I had to hike the last section through the snow to the Japan Atomic Energy Research Institute where I was reunited with my old colleagues.
Japan’s machine, the JT-60 experiment, was far larger than the H-1 Heliac in Australia. I remember entering the enormous facility and climbing up onto the colossal machine, feeling giddy about standing on a device worth billions of dollars. Up in the huge control room was a large bank of computer screens showing a live feed of what was happening inside the machine’s vacuum chamber. We watched as they powered up the electromagnets and the glow from the plasma lit up the screens for a full five seconds or more.
Later our hosts took us out to a traditional Japanese bath house in the mountains. Soaking naked in the hot spring, we all challenged each other to run outside into the snow. For many years after I would tell friends back home that I had frolicked naked in the snow with John Howard, neglecting to mention his ‘Professor’ title that distinguished him from the then Prime Minister.
Now, sitting here with Matthew, it feels like the end of an era hearing him talk about the closure of the H-1 Heliac. But he says it’s because the research has evolved and moved beyond ‘table top’ facilities that are able to be supported at a university level. Most of the world’s fusion program now revolves around the international mega-project called ITER.
The International Thermonuclear Experimental Reactor, being constructed in France, is said to be the most expensive building in the world, costing US$25 billion. It aims to be the world’s largest magnetic confinement plasma physics experiment, and the first fusion device that will be self-heated by its fusion reaction and able to support a burning plasma.
I’d heard of ITER when I was here fifteen years ago. Back then it was still in its early stages, but now its apparently well underway.
ITER is a ‘tokomak’, where the giant electromagnet coils form a torus or donut shape, similar to Japan’s JT-60 experiment (now changed to the JT-60 Upgrade). Imagine a cloud of superheated hydrogen particles whizzing around inside a donut-shaped magnetic field, like a circular race track. It’s not that tokamaks are the only way to do nuclear fusion, Matthew explains, they’re just the most understood.
Australia’s H-1 Heliac is a ‘stellarator’, which is very similar, but the donut-shaped magnetic field is twisted like a helix. Stellarators were invented to deal with some of the problems found in tokamaks, but with the development of superconducting electromagnets, tokamaks are now well ahead.
There are various smaller tokamak experiments around the world, but Matthew says he can count the number of high performance machines on one hand. There are three other large-scale tokamaks: the Joint European Torus (JET) in the UK, the DIII-D machine in the US, and the ASDEX Upgrade in Germany.
The goal is to have more power confined than is lost. Looking at all the tokamak experiments around the world they found that to get better heat retention, they needed increased size; and to achieve stronger magnetic confinement, they needed larger superconducting electromagnets. It all pointed to the need for a bigger experiment.
They calculated the size of the tokamak that was needed — it would have to be enormous, with electromagnet coils around 11m high, and the whole torus almost 20m in diameter. From this the ITER project was born. It hopes to achieve temperatures of 100-150 million degrees in its plasma core, which is ten times as hot as the centre of the sun. The magnetic field strength will be 13 Teslas, which is 280,000 times that of the earth’s magnetic field.
They’re aiming for a Q (power ratio) of 10; which means that with the input of 50MW of power to heat the plasma, they’re expecting 500MW of power to be released by the fusion reaction. Nobody has even reached a Q of 1 (the break-even point) before. The JET machine in the UK currently holds the record with a Q of 0.67.
ITER is a collaboration between the project’s 7 members: the European Union, China, South Korea, the US, Russia, Japan and India; who share in the costs of the project, and also share in the experimental results and any intellectual property that’s developed.
So where does that leave Australia? We’re apparently the first non-member country to be asked to join ITER, which means that we have the opportunity to be part of the world’s largest physics experiment at a fraction of the cost that the member countries are paying.
Matthew tells me that we’re now focused on supporting ITER through a program called the Integrated Tokamak Physics Activity (ITPA). There are three sub-fields that Australia is involved in: 1. Theory & Modelling, which is what Matthew’s team is working on, developing theoretical models of the plasmas within ITER; 2. Diagnostics, developing tools and techniques for measuring the conditions inside ITER; and 3. Fusion Materials, developing materials that can withstand the extreme conditions within ITER.
ITER is currently at construction phase. They want the first plasma by the end of 2025 (it will basically be a ‘political’ plasma, he says), the first deuterium fusion plasmas around 2030, and they’ll first start pushing the parameters around 2033. That’s still a long way away — ‘My whole career’, Matthew says.
After our chat I say farewell to Matthew and head over to the Research School of Physics and Engineering. It feels very nostalgic to walk my old familiar route through the campus, and heartwarming to see that some of the old landmarks are still there — the avenue of trees, the stream with the stepping stones — though there have been some changes too.
The facility manager, Michael Blacksell, comes out to meet me, limping due to a weekend football injury. He takes me into the fusion research facility where the H-1 Heliac is still there, mostly as I remember it.
Michael is part of the second field of ITER research: Diagnostics. He’s working with my old supervisor, Prof John Howard, who is officially retired but continuing his research near Port Macquarie with the support of the Australian Nuclear Science and Technology Organisation (ANSTO). John is a world expert on ‘coherence imaging’ technology that he developed while working on the H-1 Heliac machine. He’s now been invited to develop the ‘ITER Boundary Imaging System’.
As Michael explains this Imaging System to me it reminds me of my old spectrometer project on the H-1 Heliac, though much more sophisticated. They’re developing a device that can look at the light emitted within ITER’s vacuum chamber and analyse it to see what particles are in there. This can tell them a lot about whether the fusion process is going well, or badly, such as if it’s creating too many radioactive byproducts or vaporising parts of the metal walls of the chamber. The team is now doing the engineering to get this technology into ITER.
A lot of our discussion is around just how do you ‘look’ inside the hell that is the inside of ITER. Just creating an aperture for light to come through can put the highly sensitive device at risk. This is one of the big challenges of the project.
The third field of research supporting ITER is Fusion Materials, led by Associate Professor Cormac Corr. Cormac is currently away, but Michael shows me his work. In the same facility as the old H-1 Heliac is another smaller machine called MAGPIE 2 that will take its place. It’s smaller predecessor, MAGPIE 1, is in another laboratory down the corridor.
MAGPIE 1 and 2 are linear plasma generators that can create an intense plasma and fire it into different materials. Michael points out the glass vacuum tube inside which the plasma is generated, and says that it can only be turned on for a tiny amount of time, otherwise the glass will overheat and shatter.
He explains that the walls inside ITER’s vacuum chamber will be covered in tiles made of tungsten, which has the highest melting point of all metals. Ideally the tiles wouldn’t come in contact with the plasma, but sometimes the plasma can arc to the walls, vaporising the metal that it touches. Cormac’s team is using MAGPIE 1 and 2 to explore what happens to tungsten when it interacts with plasmas — essentially ‘what happens in hell’, Michael says.
It’s eventually time for me to leave, and I get one last photo of me alongside the old H-1 Heliac machine before it leaves the country. I remember being in awe of this machine, and I can hardly imagine what it would be like to work on a machine on the scale of ITER.
I find it incredible to think that we may have harnessed fusion power for electricity within only a couple of decades. At a time when short-term thinking seems to be the norm, here are teams of Australian scientists that are part of a world-wide collaboration, planning decades ahead. I leave ANU excited about what the future holds.
A huge thanks to Matthew and Michael for taking the time to talk with me and patiently show me around the facilities.
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