FUSION

I finished the book about the history of nuclear fusion reactor 
research that I've been mentioning lately. The title is "Fusion: 
The Search for Endless Energy", by Robin Herman. My copy is the 
first edition from 1990, which I picked up from a small bookshop 
sometime many years ago, I think before I finished secondary 
school. Like so many books, I never got around to reading it 
properly until now. There was a second edition published in 2006, 
which is still available from Cambridge University Press (for quite 
a lot more than the $15 for my second-hand hardcover):
https://www.cambridge.org/au/universitypress/subjects/physics/plasma-physics-and-fusion-physics/fusion-search-endless-energy

The author, who died last year, was a journalist (rather an 
unlikely one to cover this topic, if her Wikipedia page is anything 
to go by) and as such it's not a technical book. Key scientific 
developments are summarised at a level that's easily digested, but 
primarily as part of a narrative describing the overall history of 
the field. Key individuals in the plasma physics community, and 
politics behind the scenes of the experiments, are given as much 
focus as that applied to the technology itself. This wider context 
explains many of the motivating factors behind fusion's often 
unsteady rate of development, and of course the field's unrealised 
promises (not to mention occasional mistaken claims) of success.

I think complex technologies are always best understood on top of 
the historical narrative of their development. This book explains 
that history with ample entertaining anecdotes picked up through 
the author's own interviews at a time when scientists from the 
first generation of fusion research were still alive to tell their 
stories. At times it does ham things up a little, a bit overly 
eager to elevate the generally dry world of plasma physics 
research, but succeeds at presenting such a complex field in a 
highly readable way. It also tries to cover a global perspective, 
both sides of the iron curtain, and also peeking into Japanese 
research later in the game.

Upon finishing the book, the obvious thing to do is to look into 
what's happened in fusion research since 1990. That actually seems 
to be an interesting point in time with which to compare the 
current state of the science, because in some ways it seems that 
everything has changed yet nothing has changed.

Having documented the record-breaking giant Tokamak reactors of the 
USA and the EU, TFTR and JET, which nevertheless failed to realise 
their scientist's dreams of reaching 'breakeven', the book mentions 
the beginnings of the ITER project. With initial design work dating 
back to the late 1980s, ITER is still today the fusion community's 
one big work-in-progress, possibly nearing completion but also 
encountering new delays. In pushing for a giant international 
effort, it seems that the scientists unwittingly deprived 
themselves of continuing to build up ever bigger Tokamak-based 
reactor designs via the national programmes of their individual 
countries. In the USA, a successor project to the TFTR reactor at 
the Princeton Plasma Physics Laboratory, home of the first US 
experiments into fusion reactor design, was never realised at the 
same scale. The one commercial company that got into building 
fusion reactors during the era covered by the book, General 
Atomics, is still running their DIII-D reactor from 1986, while 
trying to raise funding to build a new design. The JET reactor in 
England is still currently the biggest working fusion reactor, with 
efforts recently focused on research to help the ITER project.

The Russian T-series Tokamaks, the origin of the design that now 
dominates magnetic fusion research, never caught up to scale of 
western designs in the 1980s since their big T-20 reactor project 
fell victim to the failing Soviet economy. But their T-15 reactor 
has also been upgraded for research contributing to ITER, and 
curiously they've also converted it to work as a fusion-fission 
hybrid. This is a little-explored, and in many circles unpopular, 
branch of fusion reactor development which is surprising to see pop 
up at this point.
https://www.iter.org/newsline/152/477
https://www.neimagazine.com/news/newsrussia-launches-t-15md-tokamak-at-the-kurchatov-institute-8757349

The Chinese have also now gone heavily into fusion research, as an 
ITER member as well as through construction of various reactors 
themselves. They've even pulled an old Stellarator out of the 
Australian National University, which seems to have been the only 
significant Australian fusion reactor known to the internet, the 
Heliac-1, built in the early 90s. So much for aussie fusion then, I 
suppose.
https://www.canberratimes.com.au/story/6033331/anu-partner-with-china-on-nuclear-fusion-technology-for-power-supply/

Outside of magnetic fusion, the latest big news has been the 
success of the National Ignition Facility (successor to the Nova 
facility described in the book) at surpassing breakeven - getting a 
fusion reaction to release more energy than is put in to start it. 
While ITER seems to have stolen the focus of magnetic fusion 
funding away from national projects, the NIF and laser fusion has 
been USA's big national project, bred out of a laser fusion 
programme which was still significantly classified at the time of 
the book's publication. After initial failure in the 2010s, NIF 
finally acheived the 'ignition' that their facility was named for 
in 2021, then 'breakeven' last December and again last month.

The trouble with this is that 'breakeven' was really intended as an 
interim target for magnetic fusion, a milestone that the big 1980s 
Tokamaks were hoped to reach, from which to plot a path towards a 
practical fusion power plant design. The difference with laser 
fusion is that whereas a magnetic fusion power plant is expected to 
reach this point of energy production through one massive injection 
of energy into a gas and then have the reaction sustain itself 
afterwards, a laser fusion reaction is one flash in the pan which 
actually blows the environment for the reaction (the fuel pellet) 
apart in the instant that it happens. Whereas magnetic fusion is 
often described as akin to putting the sun in a box, I think laser 
fusion is more akin to detonating a mini H-bomb in a box. Indeed 
this has really been the force behind laser fusion research from 
the start: studying the behaviour of fusion reactions as they 
happen in bombs in order to advance the USA's nuclear weapons 
research. The LIFE programme to develop laser fusion into a 
power-producing proposition has already been abandoned. NIF's long 
reset times, massive laser energy losses excluded from the 
breakeven calculation (vastly dwarfing actual energy production), 
and the extremely expensive (some even made with diamond) 
ultra-precise fuel pellets that are destroyed in each test, make it 
look a world away from something that could economically produce 
electricity.

But perhaps what's most different in the fusion field compared to 
in the 1990s is that these national, and now international, fusion 
programmes are no longer the only game in town. While General 
Atomics was the only private company to do significant practical 
research over the period covered by the book, there currently seems 
to be an explosion of fusion start-ups building all sorts of 
reactor designs, following both old avenues abandoned by the 
national programmes of the past, and completely new concepts. The 
same enthusiasm for green energy solutions that encouraged 
governments to back constructing the big Tokamaks following the 
1970s oil crisis, before promptly losing interest later in the 80s, 
has now gripped private investors. With the resulting new companies 
promising much shorter paths to fusion than the slow road that's 
being laid by ITER.

While it's great that many alternative avenues to fusion are now 
being investigated as part of the current green energy race, the 
fact that it's being done in the private sector has some 
disadvantages too. It means that some of the walls of secrecy that 
were first taken down back in the late 1950s when fusion research 
was declassified by the major governments, are now being errected 
again for the sake of protecting intellectual property. Much of the 
reaearch and technology is being kept under wraps by companies 
afraid of helping their competitors to reach the fusion goal first. 
The result is lots of glossy 3D-rendered animations and sales 
pitches, but frustratingly little information with which one can 
separate fact from hype. Many machines have been built by these 
start-ups in the 2010s, with their creators often claiming that 
they've learnt enough from those tests already to build a working 
fusion generator within the decade. Given that venture capitalists 
are little interested in investments that take much longer to pay 
off, perhaps that's no wonder. The promised results of public 
fusion projects seem eternally to be 20-30 years away, but perhaps 
private fusion will forever be 5-10.

 - The Free Thinker