This morning, July 1, the Italian Minister of the Environment and Energy Security Gilberto Pichetto Fratin participated in the ceremony for the completion of the superconducting magnets of ITER, the experimental reactor for nuclear fusion under construction in Cadarache, France.
For the occasion, we are publishing the interview with ITER's Director General Pietro Barabaschi, taken from issue 50 of Renewable Matter.

Reproducing the energy of the stars here on Earth. Then harnessing and using it. For decades, scientists have been debating how to recreate in a laboratory the conditions that, on the Sun, cause hydrogen atoms to fuse and turn into helium, generating enormous amounts of light and heat. Whether the experiment is achievable has actually been known since the 1950s, when fusion was first used in a H-Bomb test as part of military research.
However, harnessing fusion energy – theoretically limitless and nearly waste-free – for civilian purposes poses far greater challenges, beginning with the feasibility of the technologies and then moving the focus far ahead in time on the reliability and scalability of the systems. While the “records” on net energy gain through fusion, now announced with some frequency by various experimental reactors, have revived hopes of achieving the “Holy Grail of energy,” the timing, however, continues to be unpredictable. This does not stop economic interest, however: private investment in research has increased in recent years, exceeding 6.2 billion dollars by 2022, according to the Fusion Industry Association.
Government commitment is also growing, as evidenced by the mega project ITER, an acronym for International Thermonuclear Experimental Reactor, which is expected to receive a total of 20 billion euros over 20 years from an international consortium of seven public partners: the European Union, China, India, Japan, Russia, South Korea and the United States (the United Kingdom and Switzerland were also there until 2023).
To hear about ITER's goals, we joined Director General Pietro Barabaschi at his office in Cadarache, southern France, on the very site where the world's largest nuclear fusion facility is being built.

How was ITER born?

The idea originated in the mid-1980s, from a meeting between Gorbachev and Reagan, to be a peace project with a very ambitious goal: to demonstrate the feasibility of fusion energy for civilian purposes. The project was then expanded to Euratom (representing the European states) and other members. In the 1990s, we had the design phase, which was then followed by a setback since a site for construction would have to be found. Once a suitable site in France was identified, the agreement to establish a full-fledged international body was signed between 2006 and 2007, and I have been its director general since 2022. ITER's goal is to build a large research facility here in Cadarache.

How is the project funded?

It has no private funders; it is all publicly funded. From a practical perspective, the project is based on supplies in kind, that is, divided among the seven stakeholders. There is a central budget for a range of activities related to design and assembly, and then there are national agencies responsible for supplying the components. But since they are all first-of-a-kind components, that is, never manufactured before, cooperation is key. In Cadarache we have about 1,200 permanent employees of the international body, another 300-400 people who come and go, and about 4,000 contractors working in the implementation phase.

Given the consortium's great internationality, could geopolitical unrest at this time affect the progress of research?

I would say no. Despite strong cultural differences and current tension, I must say that it is pleasantly surprising how we all remain fairly aligned on an important goal and try to make it work.
There are then organisational complexities that transcend the current geopolitical problem. One can easily imagine that arranging so many contributors, with different professional cultures and various visions of how major projects are carried out, would be no small feat. A challenge, however, that offers an opportunity to learn how to accomplish something together: if you will, it is also an experiment in social policy.

Let's start with the basics: how do you produce nuclear fusion on Earth?

Unlike fission, which can be accomplished essentially at room temperature, the fusion reaction needs to keep the reagents at high density and high temperature.
There is a very high density on the Sun, caused by intense gravitational forces, and this results in fusion between hydrogen nuclei, which is essentially the source of most of the energy produced on our star. On Earth, this cannot happen and so fusion must be produced at much lower densities with other reagents, namely tritium and deuterium, two isotopes of hydrogen that are easier to fuse.
The problem is that the nuclei of the reagents are both positively charged, which means that they mutually exert a repulsive force: they basically don't want to come closer together. So we have to get them close enough to collide; then they will fuse, generating energy in the form of neutron fluxes. For this to happen, a very high temperature is required, between 100 and 150 million degrees Celsius.

And how do we get to 150 million degrees?

It starts with a strong electrical discharge. The current passes through a huge donut-shaped metal structure, the tokamak. The heat generated by the current brings the atoms to the plasma state (the so-called fourth state of matter, a kind of very hot and electrically charged gas composed of positive ions and free electrons, editor’s note).
The first problem that arises at this point is how to keep this “soup” of nuclei and electrons stable and bring it to even higher temperatures so that fusion can take place. In order to accomplish this, at ITER we will use the magnetic confinement method: that is, very strong magnetic fields are created with huge superconducting magnets, but these need to work at very low temperatures. So imagine the complexity of having 150 million degrees Celcius on one side and -270 °C within a metre's distance on the other!
Magnetic fields keep the plasma detached from the walls of the tokamak so that the heating process can continue, taking it from temperatures of hundreds of thousands of degrees to over a hundred million degrees. It is basically a giant microwave oven. The challenge is to minimise heat loss with a thermal insulation system, which is precisely the “confinement.” All the various records that are reported in the newspapers are nothing more than progressive adjustments of the plasma confinement, which allow more and more energy losses to be minimised.
The question that arises, at this point, is how to harness the energy generated by fusion. In power generation plants you use a coolant, usually water: you bring it to a boil and the steam generated will turn the turbines. But if I have to keep the plasma at 150 million degrees, I cannot put water in the middle of it. So you have to place the heat exchangers (which will be “bombarded” by the energetic neutron flows) on the outer surface: this is an inherent problem of fusion, which requires very large scales.
These are therefore new, complex technologies that must be put together in a device whose geometry is anything but simple. Compared to a fusion tokamak, the so-called “light water” reactor, which is the main tool for harnessing the fission reaction, is incredibly simple.

We talked about magnetic confinement. How does inertial confinement, studied in other types of fusion reactors, work instead?

These are conceptually vastly different methods. For inertial confinement, instead of starting with a gas, you start with a grain of ice consisting of deuterium and tritium. You bombard it with lasers that generate very powerful energy for a really short time. This allows the ice kernel to reach a very high temperature and, instead of exploding, it implodes, reaching a state of very high density similar to what can be found on the Sun. This achieves the conditions for thermonuclear fusion for a very short time, generating considerable energy.
The problem is that it is not a continuous process. While magnetic confinement is based on the idea of producing energy from plasma continuously, with the inertial method you have a series of micro-explosions of energy, and that is not very practical. Let's say my power plant needs to produce a gigawatt of power: that means generating 1,000 megajoules every second, and if each experiment only gives me a few megajoules, I will need hundreds of these micro-explosions every second to achieve my goal. Currently, there is no way to do such a thing, and in my opinion, it will be very difficult to get there.

Instead, as you said, with magnetic confinement, there is a continuity in production…

We start with this idea, but we are not there yet. At the moment, we are aiming to do experiments that last for at least ten minutes, and not just a few seconds. This is, in fact, the order of magnitude of time for the engine of a car, for example, to come up to thermal speed. That would be quite an achievement.
Next, however, it will be a matter of going from 10 minutes to 10 years, that is, reaching the goal of reliability. For it is one thing to demonstrate the principle, the feasibility, it is another to demonstrate the commercial practicality of the technology. And I say this clearly, as I would rather not raise exaggerated expectations.

The challenge in the coming years will therefore be to prove the reliability of the technology?

At the moment we know that fusion is feasible. We have enough information to know that it can work for a few seconds. We also know that we can obtain more energy than we put in. With ITER, the goal is to see if it is possible to integrate the technologies in such a way that we can start the engine and run it for fifteen minutes at full power. Like in Formula One, if we want to put it that way. The big question that comes next is, once we have cranked up the engine and won the race, can we also send people around all day in the same car?
The ITER research will precisely serve to understand what the impact of nuclear fusion might be on society, demonstrating its reliability, but also its accessibility and cost.

Speaking of expectations, what can you tell us about the timeline? When will the ITER work be completed?

I am not at this time authorised to give an answer to this question.
I have been back at ITER for a year and a half as director, having worked there back in the 1990s and until 2005, when I left to take charge of two other projects (including JT-60SA, currently the world's largest tokamak). Under my leadership, we have developed a new baseline for the work, which I will present to the stakeholder council in June, but until then, I cannot give any indication of the timeline. What I can say is that we are quite far along in the project, but there is still much to be done and completion will not be imminent.

More generally, when would it be possible to produce energy with fusion? Some say in 2050…

The correct question should be: when will it be possible to produce fusion energy in a way that is an asset to society? It is a question I ask myself every morning when I wake up, and it is more than legitimate. But the point is that we are moving into uncharted territory.
In the next 10 years we will certainly move forward in demonstrating feasibility, but then persuading utilities to build reactors to produce power continuously will be a much harder road. Of course, unexpected breakthroughs cannot be ruled out…
I know many people like to make predictions stating “in 30 years,” or “in 50 years,” but I prefer to be more cautious and frankly say I don't know.

Let's talk about raw materials. If deuterium is found in nature, tritium, on the other hand, is obtained from lithium…

Tritium is not naturally occurring because it is radioactive, even though it has a decay of only 12 years. This means that it must be manufactured. It is generally a by-product of conventional “heavy water” reactors, so we can use it at this starting stage. But in the future, if we want to develop fusion technology, we will either have to find other reagents (and there are people working on this) or fabricate tritium directly on site, with a technology called breeding. In ITER, we will test this system to a small extent, but I hope there will be more research on this challenge.

Could the use of lithium, which is already on the Critical Raw Materials lists, compete with the battery industry?

There might be some competition, but large amounts of lithium are not needed for fusion. I don't think this will be a real problem.

Let me ask you one last question: what do you say to those who claim that we are wasting resources on research that will not bear fruit anytime soon?

In my opinion, in general, all funds for research into alternative energy sources are money well spent. Then a comparison should also be made with the amounts that are spent in Europe on fossil fuel supply (fossil subsidies in the EU came to 123 billion euros in 2022, editor’s note). In short, proper proportion must be made.
And finally, there are always great rewards for society from research, because many of the technologies developed can then be used in various fields, often different from the original one. Think of CERN doing research on particle physics. One might say: what's the point? But in fact, so many technologies that we take for granted today were developed thanks to CERN or places like that.

Cover image: ITER, the Tokamak pit (ph Luigi Avantaggiato)