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Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

imperial.ac.uk

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Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#161

Post by jjk166 »

kragen wrote: post #127
tsimionescu wrote: post #120

Earlier quoted context omitted.

Because to achieve 1MW of energy from fusion, you put 200MW of power into the lasers. And, you have to fire these lasers with unfathomable precision at a tiny piece of gold, in order to heat up an even tinier pellet of hydrogen, which then heats up enormously for a few milliseconds before fizzing out. ICF is a good way of studying what happens inside a hydrogen bomb, but it is in no way imaginable how you could use i…

What stops you from using the "even tinier piece pellet of hydrogen"[sic] from initiating fusion in a slightly less tiny pellet of hydrogen that it's sitting on top of, which initiates fusion in a slightly less tiny pellet of hydrogen, and so on? Aside from concern for your own survival, of course. Maybe if you can't fathom the precision required to irradiate the NIF hohlraum sufficiently isotropically to achieve ign…

Nuclear fusion requires both compression and heating of the fuel. In nuclear weapons, this is accomplished with a combination of radiation pressure and a fissile sparkplug, respectively. In inertial confinement fusion, there are two distinct laser pulses with different characteristics. A fusion pellet detonating would release radiation that could compress another pellet, but there would be no method of heating that pellet at the appropriate moment.

There may be an engineering method to overcome this, but it would be way beyond the difficulty of getting that first pellet to ignite, which already is a bleeding edge technological development.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#162

Post by hpcjoe »

rfrey wrote: post #61

Meta-question about fusion energy -something I don't understand about the movement. I spent a few years as CTO of a company providing heat-to-electricity plants. We financed and built them off high-heat plants like natural gas turbines. The "fuel" was heat going up the stack - so it was essentially free. We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada. G…

Very likely, each fusion plant (if they ever exist) would require, ironically, a fission plant next door to provide the power required for the magnets.

The magnets, and wiring won't be cheap. The power delivery and control won't be cheap. I'm not sure how this would be amortized into the cost of the power, without making it 2-3x (or more) more expensive than alternatives.

We can build, and we need, nuclear plants now, to be able to generate cheap/plentiful electric power. And if we don't we're basically going to have to push the brakes on EV deployment. Or light up more NG/Oil plants to provide the power for those.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#163

Post by Animats »

rfrey wrote: post #61

Meta-question about fusion energy -something I don't understand about the movement. I spent a few years as CTO of a company providing heat-to-electricity plants. We financed and built them off high-heat plants like natural gas turbines. The "fuel" was heat going up the stack - so it was essentially free. We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada. G…

Doing something with low-grade heat is hard and often futile. E = (Th-Tc)/Th. Look at a gas turbine. There's a succession of turbine wheels, getting larger towards the end. Each is running off the exhaust of the previous wheel, at a lower pressure. If you added another, larger, turbine wheel at the end, you'd get a little more energy out, at higher machine cost. The turbine ends where adding another wheel is not cost-effective.

Starting from the exhaust at that point means you're competing with turbine manufacturers who decided they'd reached the economic limit. That's fighting the Second Law of Thermodynamics.

The hot end temperature for fusion systems is quite high. Tens of millions of degrees at the plasma. Fusion has lots of problems, but thermodynamic efficiency is not one of them.

The dream is that somehow that high temperature plasma from the fusion reaction is run through a hollow coil to generate power by magnetohydrodynamics. No turbine required.

Somehow. Maybe someday. No clue how to do this yet.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#164

Post by cletus »

bigfudge wrote: post #157
cletus wrote: post #146

Earlier quoted context omitted.

> How is fusion different? It's not but people don't seem to realize this or maybe just don't want to think about it. Spending $100B to produce 1GW of power (made up numbers) is not an economical source of power. So hydrogen being free (deuterium and tritium are essentially free; Helium isotopes are more complicated) is irrelevant until the capital cost of the plane is much, much lower. And even then you still have t…

> photos created at the Sun's core take ~30,000 years to escape I’m guessing you meant photons but this still seems amazing. Is there somewhere I can find out more about that?

So this is based on mathematical modeling. Here's one reference I found [1] that estimates 5,000 years. I know I've heard 30,000 too, which is really within the same order of magnitude.

[1]: https://sciencing.com/fun-sun-moon-stars-8459789.html

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#165

Post by cletus »

zpeti wrote: post #158
cletus wrote: post #146

Earlier quoted context omitted.

> How is fusion different? It's not but people don't seem to realize this or maybe just don't want to think about it. Spending $100B to produce 1GW of power (made up numbers) is not an economical source of power. So hydrogen being free (deuterium and tritium are essentially free; Helium isotopes are more complicated) is irrelevant until the capital cost of the plane is much, much lower. And even then you still have t…

$100bn to get to a working fusion reactor doesn’t mean the second one will cost €100bn as well…

Oh for sure. To be clear, I meant the amortized cost, not the initial cost of, say, ITER. I could've stated that better.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#166

Post by andy_ppp »

dragontamer wrote: post #104
Andrew_nenakhov wrote: post #90

Earlier quoted context omitted.

"We should put more resources into breeding faster horses now, internal combustion can wait." - someone in late 19 century.

The benefits of a car were immediately obvious as soon as supply lines were considered. Feed for horses was something like 30% of all deliveries in a horse-based supply chain. Railroads run off of coal, but steam-engines were huge. ICE engines were miniature engines that also ran off of a fuel source (eventually settling upon oil, but many different fuel sources were considered in those early days, including electric…

I wonder if it’s possible to create air conditioning that generates electricity. It seems like you’re removing energy from the air.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#167

Post by wussboy »

stormbrew wrote: post #136
rfrey wrote: post #61

Meta-question about fusion energy -something I don't understand about the movement. I spent a few years as CTO of a company providing heat-to-electricity plants. We financed and built them off high-heat plants like natural gas turbines. The "fuel" was heat going up the stack - so it was essentially free. We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada. G…

> We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada. Worth noting that the current plan is for the minumum carbon tax in canada to increase by $15/tonne/yr until 2035, so the question might be more when will it reach a break even point? Seems like you'd want to be positioned for that.

That kind of forward thinking is unfortunately rare.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#168

Post by [deleted] »

after_care wrote: post #141
jhallenworld wrote: post #99

Earlier quoted context omitted.

Hah, well what was the rate of progress on breeding faster horses vs. internal combustion in the late 19th century? I don't imagine that the progress rate was very high for horses..

I want to live in a world where we work on projects that will benefit us both 5 and 50 years in the future.

[deleted]

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#169

Post by eldaisfish »

jhallenworld wrote: post #84
rfrey wrote: post #61

Meta-question about fusion energy -something I don't understand about the movement. I spent a few years as CTO of a company providing heat-to-electricity plants. We financed and built them off high-heat plants like natural gas turbines. The "fuel" was heat going up the stack - so it was essentially free. We still couldn't compete with conventional electricity plants, even with a $30/tonne price on carbon in Canada. G…

Study this: https://www.lazard.com/perspective/levelized-cost-of-energy-... Ignoring storage: it makes no sense now to build anything but wind and solar. Only the marginal cost of gas is cheaper (meaning existing plants, not new ones). Including storage: conventional is still cheaper, but not by much (within a factor of 2): $81 for PV+storage vs. $44 for gas combined cycle. We should put more resources into storage n…

Lazard do not factor in the cost of accommodating the vagaries of wind and solar into these figures.

As just one example - when the wind turbines aren’t running, your lights are still on. That power comes from somewhere and that somewhere has a cost to keep it available.

That cost is passed on to electricity consumers but not the source of the problem - wind and solar generators.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#170

Post by kragen »

jjk166 wrote: post #161
kragen wrote: post #127

Earlier quoted context omitted.

What stops you from using the "even tinier piece pellet of hydrogen"[sic] from initiating fusion in a slightly less tiny pellet of hydrogen that it's sitting on top of, which initiates fusion in a slightly less tiny pellet of hydrogen, and so on? Aside from concern for your own survival, of course. Maybe if you can't fathom the precision required to irradiate the NIF hohlraum sufficiently isotropically to achieve ign…

Nuclear fusion requires both compression and heating of the fuel. In nuclear weapons, this is accomplished with a combination of radiation pressure and a fissile sparkplug, respectively. In inertial confinement fusion, there are two distinct laser pulses with different characteristics. A fusion pellet detonating would release radiation that could compress another pellet, but there would be no method of heating that p…

Thank you very much!
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