Laser Fusion produced excess energy.

[Diogenes]

Laser Fusion Project Takes One Small Step Toward Energy Leap

Two of their best shots took place on Sept. 27 and Nov. 19 of last year. The researchers figured that about 10,200 to 12,000 joules of energy were absorbed by the fuel in September, and yielded 14,400 joules in return. The November yield was even better: 8,500 to 9,400 joules went into the fuel, and 17,300 joules' worth of energy came out.

http://www.nbcnews.com/science/science- ... eap-n27796

[GIThruster]

Didn't they finally say about 6 months ago they were not expecting to break even?

[Skipjack]

They are far away from break even. The article is (purposely?) misleading. They put 500 Megajoules of electricity into the lasers to get 17 kilojoules of power out of their hohlraum. It is just more of the typical NIF hyperbole.

[ladajo]

Maybe the issue lays not with the lab but with the reporting.

The key point here is that they are finally getting net fusion results from the fuel. That is a good thing.

The getting of energy to the fuel and efficiency in doing so is a whole nother discussion. The point is clear.

They suck at moving energy via the facility to the target. The target engineering and energy application methodolgy is now much improved in that energy absrobed by it now produces more out and is repeatable.

So, it is a big deal.

Now we need to take a hard look at what it takes to get the energy applied to the target and absorbed.

One of my questions is how much actually is aimed at the target verses how much is absorbed? Not how much is absorbed, vice released.

So if you show me a floor diagram of the facility and chart over it energy levels and flow, it would be interesting to see where the big inefficinecies are and what can be done about them.

It may seem that the cruxt of the issue is that you need to fire a ridiculous amount of power at the target to get it to absorb enough to create the reaction. But is this the bottom line?
If so, what options are available to mitigate or improve it?

This is the part the article glosses over IMO. I am sure the lab would love to talk about it if asked.

[Skipjack]

Sorry but this is nonsense. If we start calling this net gain, then by all means we can start claiming that all sorts of other fusion methods have achieved net gain years ago. It is just a matter then of how you twist the math. That can not be it!
And this is not just a matter of improving inefficiencies in the facility. The conversion of electric energy into laser energy already costs a factor of 250 (500 to 1.9 megajoules). By the time the laser has finally reached the target, it is only 10 kilojoules or so. So all this math is absolute nonsense! Besides the whole concept will never lead to economic fusion reactors, not matter how much you improve on it. From what I understand each hohlraum is precision manufactured and gold plated. There does not seem to be much room for tritium breeding either. The whole thing is gigantic too, so the initial capital investment is huge. It just does not work for energy production and quite frankly, I could care less about the other uses. It is a technological dead end and therefore a waste of money.

[mvanwink5]

The problem with subtle dishonesty, as propaganda is surely a variant, is that the government itself has no idea what is what, where the truth lies. So, when a dark horse makes a real break those idjuts won't know what or who to believe, no internal yardstick to use to make a truth judgement. Liars' dilemma...

[ladajo]

Sorry but this is nonsense. If we start calling this net gain, then by all means we can start claiming that all sorts of other fusion methods have achieved net gain years ago. It is just a matter then of how you twist the math. That can not be it!
And this is not just a matter of improving inefficiencies in the facility. The conversion of electric energy into laser energy already costs a factor of 250 (500 to 1.9 megajoules). By the time the laser has finally reached the target, it is only 10 kilojoules or so. So all this math is absolute nonsense! Besides the whole concept will never lead to economic fusion reactors, not matter how much you improve on it. From what I understand each hohlraum is precision manufactured and gold plated. There does not seem to be much room for tritium breeding either. The whole thing is gigantic too, so the initial capital investment is huge. It just does not work for energy production and quite frankly, I could care less about the other uses. It is a technological dead end and therefore a waste of money.

I agree that as it stands it is not a viable method.

However, I think you are missing the trees that make the forest.

Problem: Crack a nut.
Hypothesis: If I smack it hard it will crack:
Experiment: Smack nut with sledgehammer, see if it cracks.
Process: Nut is unstable and rolls around, making it hard to hit with sledgehammer. But sledgehammer looks like plenty of force if it hits.
Adjustment: Make holder for nut to allow sledgehammer to hit.
Results: Sledgehammer cracks nut. Smushes nut in fact.
Conclusions: Nut can be cracked. Possible to refine size of hammer required, now that I know nut can be cracked.

New Hypothesis: A hammer half the size can crack the nut...

And so on.

In NIF's case, they have focused so far to making and hitting a fuel package to get it to fuse. Ultimate goal to date has been for package to produce more energy than it absorbs. They made sure that they had a big enough hammer to get sufficient energy to the package for absorption.
Now, it is my opinion that they can look at improving absorption and delivery. They have proven that for a given amount absorbed, they can get more out.
So, how can they scale up output of the fuel and scale down input of the required laser power? The previous question was, can we get the fuel to fuse releasing more power than what it takes to initiate? So now I would expect to see them working on getting the overall facility power requirement down. Improve absorption.

They are still a long way off with NIF. But this is a positive development for sure. To see it any other way is just plain silly.
Will they get beat by someone else? Maybe. But so far, no one else is publically admiting being closer.
The real bonus is that this means they will be able to make a major advancement in weapons simulation work. NIF's main purpose.

[mvanwink5]

Ladajo,
We already know fusion works (better than break even). The claim is their process (not fusion) is better than break even. All that they have shown is that fusion is better than break even. However as a research project there is knowledge that they have gained about stable compression, important, yes, but that is not what is being sold here. They cooked the books to get funding. There is a steep price to pay when books are cooked. Call it the CharlesKramer blowback. Put his brother in the position to make a funding decision after trust is lost and guess what happens.

[Skipjack]

But the NIF has not path towards a smaller hammer. It is a technological dead end when it comes to energy production. It just cant result in an economic fusion reactor design. Besides, they have tried the smaller hammer before...
My biggest problem with it is that it takes money away from other, more viable approaches. Even in laser based fusion there are other designs that seem more viable (see recent report about a European effort published in Nature).

[ladajo]

The claim is their process (not fusion) is better than break even

Can you show me where NIF said that?

Skip:
Yes, they are spending money, but remember that the real funding they get is based in the weapons work, not fusion. They use the Fusion bit to sqeeze a little more from the lemon. Welcome to Free Market.

NIF is never mean to be a power plant, but if they continue to monkey around and find a means to improve efficiencies why not try? It seems that improving the lase to absorbtion ratio is certainly doable. I would think much easier than getting absorption to fusion ratio greater than 1.

[Diogenes]

The claim is their process (not fusion) is better than break even

Can you show me where NIF said that?

Skip:
Yes, they are spending money, but remember that the real funding they get is based in the weapons work, not fusion. They use the Fusion bit to sqeeze a little more from the lemon. Welcome to Free Market.

NIF is never mean to be a power plant, but if they continue to monkey around and find a means to improve efficiencies why not try? It seems that improving the lase to absorbtion ratio is certainly doable. I would think much easier than getting absorption to fusion ratio greater than 1.

What are the efficiencies of the FEL laser? I would expect d@mn high. If they can demonstrate that the effect works, (Laser induced fusion) perhaps they can improve energy transfer efficiency to the point of making a viable system.

I know one of the commenters works with a FEL, perhaps he can put us some knowledge.

[mvanwink5]

Ladajo,
That is not the way misinformation is done, the truth is hidden in lack of clarity, and in not correcting intended misperceptions. My friend emailed me the article and he believes they achieved net in real terms, not in cooked book government terms, and he is an engineer. Do you think anyone with lay knowledge, or even technical knowledge knows how far the article and claim is from the truth? That is not by accident, but I won't push the case any further, I don't believe in doing that. Whatever.

[Skipjack]

It is not just about the laser absorbtion rate. The lasers need 500 mega joules of energy input for less than 2 mega joules laser output. That is a factor of 250 right there. Then 10 kilojoules of those 1.9 mega joules finally get absorbed by the hohlraum for 17,000 joules output. So we are talking a factor of almost 30,000 here! If you want to do math tricks then we might just as well go back to tokamaks, since they have demonstrated net gain in 1998 with the JT60.
The problem with NIF is that it will never lead to an economic fusion reactor. First of all, the hohlraum is plated with gold, it has to be very precise and be placed at the exact center for every shot and you have to do that several times a second. So essentially you are evaporating several grams of gold a second there. Then there is currently no envisioned way how to harvest that energy that can be designed around the system. Then we have the problems with breeding and managing the tritium. Where do the breeding blankets go? How do you extract it. Not to mention that the whole thing is way to big and will demand a huge infrastructure around it. The whole thing will be damaged by the neutrons in no time too. In a sense they have the same issues toks have, but worse and they are behind tokamaks too. That is why they make big press releases like that to get the attention of the gullible public. I am afraid that when someone really achieves break even, no one will pay attention thanks to their propaganda.

[hanelyp]

What are the efficiencies of the FEL laser?

I understand the good designs can be much better than %50 using electron beam recirculation.

Then again, why use the particle beam to generate a laser instead of directly driving the fusion target?

[ladajo]

Ladajo,
That is not the way misinformation is done, the truth is hidden in lack of clarity, and in not correcting intended misperceptions. My friend emailed me the article and he believes they achieved net in real terms, not in cooked book government terms, and he is an engineer. Do you think anyone with lay knowledge, or even technical knowledge knows how far the article and claim is from the truth? That is not by accident, but I won't push the case any further, I don't believe in doing that. Whatever.

So your friend did not stop and think?

I understand what you are saying, and again point out that it was the article that did the talking, not the NIF folks.
NIF never said they got net power. They said they got more power out of the pellet than it absorbed. It fused.

I really do see what you are getting at, and agree that the article has a misleading tone, like its headline. But it was the writer, not NIF, that did that.

No worries.