Producing energy by means of fusion – the same process that powers our sun – would mean clean energy in such abundance that we could afford to suck CO2 out of the atmosphere. It would mean the end of all the hazards surrounding conventional nuclear plants, since a fusion reactor can’t have melt-downs and produce negligible amounts of radioactivity. It could even provide a feasible way of taking care of all the nuclear waste that we’ve ever produced.
The catch: It’s not trivial to make fusion work. Our smartest scientists and engineers have been at it for the better part of a century.
That’s why it’s so exciting that a real breakthrough is now in the making, and that it’s happening right here at KTH. To understand why Novatron might be such a huge deal, let’s go through some basic physics and just enough of a history lesson.
Science-wise, there are three factors which matters if you want a fusion reaction that produces more energy than it consumes. Those are plasma temperature, plasma density, and energy confinement time.
That means you can either take a high or a low density approach to fusion.
High density fusion is what happens inside a hydrogen bomb, where a fission based detonation kicks off uncontrolled fusion.
*Controlled* high density fusion is called inertial confinement. This happens by blasting very powerful lasers at a small solid state fuel pellet. It’s a method that’s been seen as exotic; interesting rather than promising. But just the other day, inertial confinement seem to have yielded a net energy output. While this event – known as ‘ignition’ – is a major milestone, inertial confinement as a method is a by-product of weapons development and is unlikely to ever lead to energy production.
In the opposite ring-corner is where we find the the vast majority of fusion initiatives. The idea here is to work with minimal amounts of fuel; a few grams worth of Tritium/Deuterium, heated to a low density plasma of about 150 million degree Celsius (that’s ten times hotter than the core of the sun).
Powerful magnets are used to contain the plasma. In theory the fields of these magnets can be open or closed, but in practice closed field designs have always been dominant. Until now, that is. But before we move on, let’s take a brief look back.
One of the very first closed magnetic field reactor designs was developed in Los Alamos in the early fifties. This was in the optimistic aftermath of the Manhattan project when everything seemed possible. Perhaps it wouldn’t be too hard to take the step from fission to fusion. Hence the reactor was dubbed…
the Perhapsatron
The Perhapsatron didn’t work out, but the generally hopeful atmosphere would remain for a while. Only a few years later, on the 25h of January 1958, readers of the British tabloid The Daily Mail were greeted by the following headline:
“Unlimited Fuel for Millions of Years!”
The background was this: We’re at the height of the Cold War, and the race towards fusion based power is one of its key arenas. the British experimental fusion program ZETA had shown results which were so promising that the person in charge – Nobel laureate Sir John Cockroft – had hastened to tell the press he was “90 percent certain” that sustained fusion had indeed been reached. It turned out to be a false positive, but by the time the scientist had figured that out, the media had already whipped itself into a frenzy.
Since then, quite a number of real or imagined milestones have been passed:
1968: British scientist Mike Forrest manage for the first time to measure plasma temperature using laser spectrometry. His results confirm that the Soviets are leading the race, reaching ten million degrees Celsius inside their tokamak reactors.
1977: A decision is made to build the “Joint European Torus” in Cullham, UK. This experimental reactor was meant to run for just ten years, but remains operational to this day (it’s now scheduled for decommissioning in 2024).
1985: Michail Gorbachov and Ronald Reagan meet in Geneva and agree to join forces (together with 32 other nations) in the pursuit of fusion energy. This is extraordinary given the two super powers are still locked in deadly rivalry on all other frontiers.
1989: The chemists Martin Fleichmann and Stanley Pons claim to have produced fusion at room temperature, submerging Palladium electrodes into deuterium oxide. The results can’t be replicated but that doesn’t stop Google from investing tens of millions of dollars into the moon shot.
2006: More than two decades after the Reagan-Gorbachov accord the ITER agreement is signed. It’s the most ambitious international research project ever, and it will eventually result in building the worlds biggest tokamak reactor, scheduled to produce 10x the energy it takes to power it. (In comparison, the inertial confinement breakthrough mentioned above, produced an output of 2,5MJ from an input of 2,1MJ, and that’s not counting the energy it took to power up the lasers).
2020: The People’s Daily reports that the Chinese reactor HL-2M briefly reaches 150 million degrees Celsius. Meanwhile in South Korea, the KSTAR reactor sustains 100 million degrees for a record 20 seconds.
Which brings us to the present day.
So what will be the next major milestones? We can expect important proof-of-principle’s from ITER in the next one to two decades, but that project was never meant to produce power to the grid.
Another candidate is the well funded American initiative Commonwealth Fusion Systems. They are planning to build a real power-to-the-grid reactor, but their design is built around the same tokamak concept as ITER. The tokamak was invented by Soviet scientists in the late 50’s, and it relies on closed magnetic fields.
In spite of its popularity, the limitations with closed magnetic field confinement have been known for a long time. Here’s from a twenty year old report issued by the US department of energy:
Closed systems, with no known exceptions, show confinement that is dominated by turbulence- related processes, rather than by “classical”, i.e., collision-related, processes. As a result, to achieve confinement adequate for fusion power purposes in, for example, the tokamak requires that it be scaled up in size and power level to the point that its ultimate practicality as an economically viable source of fusion power is open to question.
In other words: closed magnetic field confinement might eventually work, but even if it does it’s going to be complicated and expensive. Possibly to the extent that reactors based on closed magnetic fields can never be a competitive alternative to fission or fossil based energy production.
As mentioned previously however, there’s also the option of building your confinement strategy around *open* magnetic fields. This is done using some version of magnetic mirrors, creating a so called magnetic trap.
The approach showed some promise in the early years of fusion research and the Lawrence Livermore Laboratory even built a testbed. It was called the Mirror Fusion Test Facility and scheduled to come online in 1986. Since Ronald Reagan felt that the energy crisis was over by then however, the whole project was mothballed the *day* after construction was completed. We’ll never know if the Mirror Fusion Test Facility could have worked.
Ever since this set-back, open field confinement has been considered a dead end. That could now be about to change with Novatron, which leverage the fundamental physics of plasma to create a containment that escapes much of the complexity of the closed field alternatives. If a tokamak is like trying to keep a giant red hot donut of a plasma in shape by orchestrating the operations of a gazillion super conductive magnets, the plasma inside a Novatron reactor will be like a ball in a bowl, naturally seeking the lowest point of the topology. Think of it like Judo, but for plasma.
We still don’t know exactly what the Novatron patents cover, but it seems they found a way to increase stability of confinement without relying on the type of cryogenically cooled superconducting magnets that is common to practically every other reactor design out there. Using conventional copper electromagnets instead, means it should be possible to build radically cheaper and smaller fusion reactors.
Just how radical, is evidenced by Novatron’s roadmap; the team is planning on having the first generation reactor up and running within a year from now. The fourth generation, which will produce energy to the grid, will come online in during the next decade.
If everything goes to plan, I think it’s quite likely that the inventor Jan Jäderberg can look forward to a Nobel prize.
That’s a big *if* of course. But to back up Novatron’s claims, it’s interesting to see that Kenneth Fowler of UC Berkeley – author of The Quest for Fusion and probably the world’s leading authority on the subject – says Novatron indeed appears to be “the missing link”.
So it’s a very real possibility that the scientific hurdles have now finally been scaled. If that is so, it’s now time to face the million big and small engineering problems that needs to be solved as the Novatron – which so far has only been proven in simulations – gets built in actual reality. Bridging this sim-to-real gap is notoriously tricky, but if the underlying science is solid there’s no magic to it, it should be merely very difficult.
The one big challenge that remains however, and that often proves to be the hairiest to overcome, is political in nature. Because even if fusion based energy production is now technically within our grasp, it can only happen provided that we join forces and really commit.
Making fusion work will come at a steep price tag. ITER already massively exceeded its €6 billion budget. Commonwealth Fusion Systems has raised $2B to date. I don’t know anything about Novatron’s funding plans, but it’s a safe bet that lots of cash will be needed.
Still though, let’s take a step back and put these numbers in perspective. However you chose to do the math, the cost of developing fusion energy is still dwarfed by the $220 billion budget of the recent World Cup in Qatar.
So the real question at the end of the day, as so often with innovation, is: how badly do we want to make this work. I for one feel more hopeful than ever that we’re now finally at the point where fusion will actually deliver on its promise.
SOURCES
I owe many of the facts and insights of this post to the British physicist and writer Sharon Ann Holgate and her recent book Nuclear Fusion : The Race to Build a Mini-Sun on Earth. More than that, I’m in debt to Per Niva, physicist and engineer at Novatron, who’ve indulged my many questions and also had the great patience to proof read this post before publication. Thank you Per, and best of luck on your journey!