Carrion Luggage

Light the Fuse

The article I'm sharing today, from Knowable, is almost two years old. That matters in this case, because I've followed this technology somewhat, and more advances appear to have been made. Nevertheless, I'm tackling the topic.

     Pursuing fusion power  
Scientists have been chasing the dream of harnessing the reactions that power the Sun since the dawn of the atomic era. Interest, and investment, in the carbon-free energy source is heating up.

"Heating up." Snort. Look, if a headline doesn't contain a pun, I'm usually disappointed.

For the better part of a century now, astronomers and physicists have known that a process called thermonuclear fusion has kept the Sun and the stars shining for millions or even billions of years.

Let's re-evaluate that sentence. The Sun is about 4.6 billion years old. The Earth, a bit younger. Life? Well, that's debatable, but it seems to have started not long after Earth's formation. Humans have been around, depending on definition, for maybe a million years. For most of our planet's history, no one cared what powered the Sun. Once we started pondering, we figured it was gods (or that the Sun was itself a god). Until, once science had advanced far enough, we figured out, to some degree anyway, what was going on in its core, which settled an earlier question about how it could be that old.

Science didn't put all the pieces together until the depths of the Great Depression, in the 1930s. Once we did, people were like, "Okay, so how can we do that ourselves?"

It’s a dream that’s only become more compelling today, in the age of escalating climate change. Harnessing thermonuclear fusion and feeding it into the world’s electric grids could help make all our carbon dioxide-spewing coal- and gas-fired plants a distant memory.

Here's where I get cynical.

For starters, the first human-made use of thermonuclear fusion was the result of people going "How can we make a bigger kaboom?" I mean, this did result in the invention of the bikini,   so it wasn't all bad. It is indeed an ill wind that blows nobody up. Or something.

Second, while I have no doubt that we'll figure this shit out eventually (assuming we don't get nuked by the kaboom version), there's a running joke that electricity from fusion power is 20 years away, and has been since about 1960. So one might forgive me for being just a little skeptical about the hype.

And for finishers, lots of inventions started with "this will be cleaner." One reason the automobile got promoted, for example, was people (especially in cities) were fed up with all the literal horseshit, and wanted something that polluted less. And, no matter what the development, someone will figure out a downside. Solar panels (a means of harnessing the power of that giant thermonuclear fusion reactor in the sky) create no pollution, but they throw shade on desert ecosystems. Windmills (also harnessing solar power, albeit less directly) make life difficult for birds (though the "causes cancer" horseshit is oil industry propaganda). Want to switch from internal combustion to electric vehicles? The battery life cycle poisons the environment, too. Point is, while no one's pointed out a downside to fusion power yet, someone will come up with something. My guess? Something to do with wasting water making the hydrogen isotopes necessary to fuel the things.

In fact, fusion is the exact opposite of fission: Instead of splitting heavy elements such as uranium into lighter atoms, fusion generates energy by merging various isotopes of light elements such as hydrogen into heavier atoms.

It's not the "exact" opposite, but close enough for a popular science article.

Doing it on Earth means putting those light isotopes into a reactor and finding a way to heat them to hundreds of millions of degrees centigrade...

You know, when you use rough but enormous orders of magnitude like "hundreds of millions of degrees," it doesn't matter whether you're talking centigrade, fahrenheit, kelvin, or rankine.

It was only in late 2022, in fact, that a multibillion-dollar fusion experiment in California finally got a tiny isotope sample to put out more thermonuclear energy than went in to ignite it. And that event, which lasted only about one-tenth of a nanosecond, had to be triggered by the combined output of 192 of the world’s most powerful lasers.

Doesn't sound like it, but that milestone was a really big deal. It made us believe that practical fusion was only 20 years away.

Again.

Indeed, more than 40 commercial fusion firms have been launched since TAE became the first in 1998 — most of them in the past five years, and many with a power-reactor design that they hope to have operating in the next decade or so.

Cynical Me: "Yeah, right, most of them are just there for the funding." And also, "You mean two decades."

None of this has gone unnoticed by private investment firms, which have backed the fusion startups with some $6 billion and counting.

Cynical Me hates being right. Oh, who am I kidding; he revels in it.

Granted, there’s ample reason for caution — starting with the fact that none of these firms has so far shown that it can generate net fusion energy even briefly, much less ramp up to a commercial-scale machine within a decade.

"Caution?" Nay. Cynicism.

In the meantime, to give a sense of the possibilities, here is an overview of the challenges that every fusion reactor has to overcome, and a look at some of the best-funded and best-developed designs for meeting those challenges.

Okay, I've spent enough time on this. The article is there if you're interested in the promised details. I really just have one more thing to comment on:

The basics of these three challenges — igniting the plasma, sustaining the reaction, and harvesting the energy — were clear from the earliest days of fusion energy research. And by the 1950s, innovators in the field had begun to come up with any number of schemes for solving them — most of which fell by the wayside after 1968, when Soviet physicists went public with a design they called the tokamak.

Like several of the earlier reactor concepts, tokamaks featured a plasma chamber something like a hollow donut...

And I'm severely disappointed that they won't call the toroid a bagel.