The bikini swimsuit was named after the Bikini Atoll. A bit of a mixup from OP though: it wasn’t named after fusion bombs. The bikini swimsuit was announced a few days after the first public fission bomb test there (Crossroads Able) in 1946. The first fusion bomb test there (Castle Bravo) wasn’t until 1954.
The sun's core is actually very hot, it is the outer layers of the sun that are much cooler. We're trying to do this at roughly twice the temperature than the core of the sun, and I realize the difference is millions of degrees but on a relative scale this doesn't add much complexity, it would be almost as difficult if the plasma would be only half the temperature that they are shooting for.
And in a way that higher temp is a result of trying to do this at a smaller scale, if you want to be net-positive it gets easier as you get hotter as far as I understand it.
So what we are doing is in fact to re-create conditions roughly on par with what is happening in the core of the sun. And it turns out that doing that small, for extended periods, net positive and reliable (without the machine suffering damage from the process) is a very hard problem. Even so I'm very much impressed with these projects, the engineering and the physics are way over my head but I do hope that one day they'll get it working. But I'm not going to hold my breath.
Incidentally, the implications for energy storage if TFA turns out to be on the money are possibly more interesting than fusion in the short term.
> what we are doing is in fact to re-create conditions roughly on par with what is happening in the core of the sun
My understanding is we are not. (Not an expert!) The Sun's core runs around 15 MK [1]. A tokamak, 150 MK [2]. Orders of magnitude rarely come for free in physics.
We need those higher energies because we can't, like the Sun, swaddle with the mass of a hundred thousand worlds a low-temperature, low-frequency weak-force mediated proton-proton reaction [3]. The Sun relies on quantum tunneling to overcome the Coulomb barrier. We humans have to increase the reaction energy so it doesn't all bleed off before anything happens [4], which means using the strong force [5].
If you start to think of 'temperature' of individual particles as 'speed with which they move' that is a useful rough approximation of trying to figure out what it means that something has a particular temperature. Containing the plasma is hard not just because of the temperature it is at but simply because it tends to destroy anything that contains it and that doesn't really change all that much for 15 million degrees Celsius, 30, 100 or 150. What it does change is that at 150 million degrees Celsius you have some hope of extracting useful work from a very small quantity of plasma. If you don't get it up to those temperatures - again, as far as I understand it - then you will always be putting in more energy than you are gaining because of some fundamental physics limitations.
So the smaller you make your reactor the hotter you'll have to make it to make it net positive. This leads to the counter intuitive result that making a much larger reactor is actually quite possibly easier than making a really small one. The rate of heat loss is much smaller for a larger reactor and so it becomes easier to sustain the reaction and to extract useful energy from it.
It is very well possible that none of the reactors currently on the drawing board and under construction are going to be working well enough to give us a sustained reaction resulting in net yield. But we're getting closer and closer to that and there is some (small) chance that I will still see this in my lifetime.
The catch is that as long as you can't get a small reactor to work getting funding for a much larger one (which you actually may be able to get to work) is going to be extremely difficult. We like to see proof before we scale up. In this case it may well be that such small scale proof can't be done or can't be done in a way that it it will convince backers that a larger scale device will work.
Yes, true. Apropos antimatter, recently I read here on HN somewhere that lightning generates antimatter as well, and it made me wonder if earthquakes do too but I haven't been able to get a clear answer on that. Fascinating stuff.
Larger reactors may simplify the plasma physics, but it complicates the materials engineering significantly. A huge problem already is creating a structure that can bear the weight of the reaction vessels and the gigantic magnetic fields used for containing the plasma, and also continue to do so for a decent amount of time after being exposed to the constant neutron bombardment of D-T fusion.
I very much doubt currently known materials and structures could be used to construct a reactor 10 times the size of ITER.
This is a high value comment - it's got a hook that I sort of mostly get, but follows that up with jargon laden things I don't understand well, and your references gave me a half hour of rabbit-hole learning. I appreciate the casual knowledge you've passed along. Thanks!
It does, actually. It's the miniaturization that's the hard part.