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Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

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Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#281

Post by hinkley »

8bitsrule wrote: post #278
hinkley wrote: post #260

Earlier quoted context omitted.

When people have been doing the propaganda for longer than I have been alive, I become an old, salty fucker.

I recall reading an old 60s issue of 'Physics Today'; someone prophesized fusion ws 20 years away. None of that in the (look, it's still around) recent article. Insightful details are present. And some honesty ... e.g. "The agency toned down the ignition objective, emphasizing NIF’s ongoing experiments to investigate materials’ behavior under extreme densities and pressures in support of nuclear stockpile maintenance…

> in support of nuclear stockpile maintenance

I may not speak for everyone but I certainly don’t find that comforting and know at least a few people who would agree.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#282

Post by walnutclosefarm »

floxy wrote: post #247
walnutclosefarm wrote: post #185

Earlier quoted context omitted.

Actually, I think the pedanticism is on the part of the people announcing this "breakthrough." The definition of "break even" used here (that is, Q>1) is highly technical, and but one factor in the actual "break even" equation. This experiment didn't prove you could get more energy out of a fusion burn than you put in (which is the notion they want to evoke), but rather that they could raise the ratio of energy absor…

>The definition of "break even" used here (that is, Q>1) is highly technical, and but one factor in the actual "break even" equation. Isn't the Qplasma > 1 the most important one here, by a very wide margin? Maybe the only important one at this point in time. That fusion begets more fusion, in a positive-feedback way. That's the breakthrough here. All the other efficiency factors are secondary in nature. That is step…

NIF achieved plasma combustion over a year ago, as documented in a Nature article earlier this year. If there is a threshold being crossed, that was it. The recent shot tuned that experiment to increase the yield. So now the the total released energy (not capturable, or usable, but released) is greater than the total non-fusion energy captured by the target (not put on the target, but actually captured and turned into useful heating and compression). But that's a completely arbitrary milestone.

And, most significantly to me, there is no argument being made anywhere that this milestone is on the path to anything other than a dead end, local optima. That is, that you can further optimized the shape, quality and size of the hohlraum, and shape of the laser pulse to get to a Q that actually has something to do with power generation. (I have no doubt that achieving combustion/ignition is useful for NIF's real purpose, which is to simulate H-bomb physics to aid in maintaining our stockpile of city-destroying weapons - they have in fact created a nano H-bomb).

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#283

Post by walnutclosefarm »

zardo wrote: post #229
walnutclosefarm wrote: post #185

Earlier quoted context omitted.

Actually, I think the pedanticism is on the part of the people announcing this "breakthrough." The definition of "break even" used here (that is, Q>1) is highly technical, and but one factor in the actual "break even" equation. This experiment didn't prove you could get more energy out of a fusion burn than you put in (which is the notion they want to evoke), but rather that they could raise the ratio of energy absor…

> This experiment didn't prove you could get more energy out of a fusion burn than you put in. Haven't H-bomb tests already proven that beyond all doubt?

Yeah, I really meant in a controlled reaction situation. Should have been more clear.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#284

Post by HarHarVeryFunny »

I'm far more excited by the innovative Helion fusion design, which unlike the NIF is intended for commercial use, and is in an advanced stage of development. NIF seems more like a way to conduct military related nuclear physiscs research rather than intended/suitable to ever be used for power generation.

https://www.youtube.com/watch?v=_bDXXWQxK38

Helion seems far more practical than the Tomahawk designs such as ITER, which seem they'll be too expensive to compete with solar/wind.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#286

Post by world-set-free »

hoseja wrote: post #62
mirekrusin wrote: post #24

Earlier quoted context omitted.

Ignition doesn't have to be net positive. It just needs to enter into state of self sustained reaction that is net positive. Ignition itself can be horribly inefficient. Nobody is designing fussion where ignition's output is directly used for the whole system to reignite again. It would be equivalent to moving hand with match that fires a match, where energy from ignition is used to trigger another hand to move anoth…

This isn't a system that can ever do a sustained reaction.

not yet

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#287

Post by world-set-free »

acidburnNSA wrote: post #136
tonmoy wrote: post #115

This type of nuclear fusion uses tritium, and since we can’t extract it from nature the only way to obtain it is very energy extensive. For this type of fusion to make sense producing tritium+lasers have to require less energy than the output, right?

The power plant version of this produces enough tritium as it captures the heat in a breeding blanket of lithium outside the core.

Lithium-6 is not as cheap as coal per energy delivered after all is said and done.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#288

Post by graderjs »

bawolff wrote: post #56
graderjs wrote: post #49

Earlier quoted context omitted.

It's not the point, having cheaper energy is not going to magically reverse priorities. Focus on what's important. Anyway, you work it out. I'm not gonna waste my time having a discussion here.

Who cares what the priorities are as long as the right result happens? If cheap energy makes incentives align so the right outcome happens, why does it matter the wrong priority caused that outcome.

You choose: no electricity for 1 month, or no food for one month? Do your priorities matter now? It matters what we get to first. Unlimited energy won't matter if everyone starved. We have multiply redundant energy, but food is vulnerable. We can't grow our food with soil that's broken and without the right fertilizer (if you don't think it's a risk look into it more).

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#289

Post by graderjs »

TeMPOraL wrote: post #127
graderjs wrote: post #25

Earlier quoted context omitted.

I don't think so. You can be doing the wrong (unsustainable thing), even if you could afford to do the right thing.

If we could afford doing the sustainable thing, but are doing the unsustainable thing anyway... that usually means we actually can't afford the right thing, or just can't do it . Note: you have to account for costs of coordination and taking on risk - then you realize a lot of the "if only everyone would ${trivial thing}..." aren't done because they actually are prohibitively expensive or downright impossible.

I think you need to look at history more. The world is not driven by rational moral actors...We could have been farming sustainably, but haven't been. It's even cheaper to rotate crops in the right way, that preserves soil, but it wasn't done. There are engine designs that are more efficient, use less gas, but gas companies held them back. There are treatments that are better, save more lives, but pharma companies would lose out if there were less chronically sick people. "Can't afford" is a dirty word. Depends on perspective, encodes morals/values. Who can't afford? The greater good? Or the greedy? Who can't afford? The present generation? Or 3 clicks down the line when everything's dead because of choices made now?

The blocker to a better world is not some engineering impossibility, or market-rational overprice...not always. Often it's because someone with some power would lose out if we changed the way we did stuff, and they don't want that.

Human fucking nature. Can't cure that. Small bore example: Your engineering org would be better without the power-mad meeting-coordinator kahuna middle manager who holds hours long meetings for no purpose than to lord over proceedings and justify their own pretense of importance. The greater good would be served by demolishing said meetings, and removing kahuna from org. Does it happen? Often, no. Why? Because the world is not driven my moral, rational actors.

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