Fusion Power Near?

[Wraith]

That is more than jsut a scaling problem.

Do the same thing, but more often. :shrug:

{edit: Further reading suggests that they believe they can keep it going without refiring the lasers if desired. After ignition they they can make it steady-state with a fusion/fission reaction. Only the pure fusion approach needs to refire lasers.}

It is a milestone, yes, but also a lower energy outputs by the way. And the entire process used in this experiment is just not suitable for power production. The actual efficiency of the overall process is still well below 10%, by the way.

The only number I saw was that it was able to achieve a better-than-expected 90% efficiency with getting energy from the lasers into the hohlraum. While talking about efficiency, you're still ignoring that they expect to get more than 100% of the input energy back out this year. I don't know how that could count as overall poor efficiency, at least not relative to the rest of the projects, since they'll be the first.

{edit: Further reading gives the expected number of 40 MJ of output for 1.4 MJ of input being expected this year or early next. First attempts to reach this will be made this summer. They will then scale it up to 200 MJ, it's unclear if the input will also scale. The experts who are working on this believe this technology will be producing a few hundred MW in the not-too-distant future, and then commercial applications can scale it to a 2000-3000 MW.}

I suggest yuo get to know me better then.

Nah, I think I'm doing alright. I of course never dreamed that you'd admit to anything, but this passive-aggresive superpatriotism is par for the course. I even expected you to try that silly attempt at turning it around on me. You keep trying to play it all down, find ways it doesn't count, saying I should take your word over the experts who actually know what's going on. At least start providing sources. I don't claim to be an expert, and I'm open to the idea that there are even better efforts out there.

Also, "isn't aimed only at power production".

Besides, if I wanted to talk down this project because it is American, I could simply talk about HiPER, which is laser driven, European, and expected to be about 100 times more efficient.

But you did try that, with JET. It just turned out to be a poor attack. Are you trying to open the door for another attempt?

{edit: Read up on HiPER. From their numbers, they're expecting about 81% the efficiency that NIF is expecting. These are expectations only though, and given the uncertainty probably close enough they can be considered roughly equal. But HiPER is also looking at a tiny fraction of the scale of NIF. NIF is expecting output in MJ, and HiPER in KJ. HiPER is going at things from a slightly different angle than NIF, so its work is still potentially valuable.}

[Flixy]

Sorry for the late reply but:

Do the same thing, but more often. :shrug:

{edit: Further reading suggests that they believe they can keep it going without refiring the lasers if desired. After ignition they they can make it steady-state with a fusion/fission reaction. Only the pure fusion approach needs to refire lasers.}

Where did you get your further reading? Because the entire process revolves around a discardable pellet which is lit up with the lasers. It burns out quickly. How on earth can you keep that going? =\

The only number I saw was that it was able to achieve a better-than-expected 90% efficiency with getting energy from the lasers into the hohlraum. While talking about efficiency, you're still ignoring that they expect to get more than 100% of the input energy back out this year. I don't know how that could count as overall poor efficiency, at least not relative to the rest of the projects, since they'll be the first.

{edit: Further reading gives the expected number of 40 MJ of output for 1.4 MJ of input being expected this year or early next. First attempts to reach this will be made this summer. They will then scale it up to 200 MJ, it's unclear if the input will also scale. The experts who are working on this believe this technology will be producing a few hundred MW in the not-too-distant future, and then commercial applications can scale it to a 2000-3000 MW.}

With overall I meant including the efficiency of the lasers, which is low, and is insanely low if you count the energy you need to calibrate it.

Nah, I think I'm doing alright. I of course never dreamed that you'd admit to anything, but this passive-aggresive superpatriotism is par for the course. I even expected you to try that silly attempt at turning it around on me. You keep trying to play it all down, find ways it doesn't count, saying I should take your word over the experts who actually know what's going on. At least start providing sources. I don't claim to be an expert, and I'm open to the idea that there are even better efforts out there.

Also, "isn't aimed only at power production".

But you did try that, with JET. It just turned out to be a poor attack. Are you trying to open the door for another attempt?

{edit: Read up on HiPER. From their numbers, they're expecting about 81% the efficiency that NIF is expecting. These are expectations only though, and given the uncertainty probably close enough they can be considered roughly equal. But HiPER is also looking at a tiny fraction of the scale of NIF. NIF is expecting output in MJ, and HiPER in KJ. HiPER is going at things from a slightly different angle than NIF, so its work is still potentially valuable.}

A couple of things.

I'm not saying NIF work isn't valuable. It is very valuable, and they have reached an important step.

My issue is with the fact that you claim to that NIF gets us close towards (commercial) power production with fusion. All I'm saying is that it isn't. Nothing to do with any anti-Americanism, which is retarded to claim to say the least, because ITER involves the USA too, AFAIK with similar budgets. It seems you are mixing up things and you don't really seem to know what you are talking about.


The setup at NIF basically works by firing a LOT of laser power into a small gold pallet which contains a tiny drop of deuterium-tritium mixture. The gold pellet is lit up by the short laser pulse, and emits a lot of X-rays which in turn heat up the D-T droplet, very symmetrically, turning it into a plasma. The entire thing is in a vacuum chamber, because otherwise you won't be able to get your lasers on target this accurately. After the explosion, which caused actual 'ignition' of the plasma (I think that's a world's first, too), the thing needs to cool off, replace the pallet and re-align the lasers.

There are quite a lot of problems with using this as a power source though.
- The laser system is tricky as hell (and that's an understatement) to align. A full power shot requires a few months to align and build up. The laser system is a couple of football fields big, and IIRC ten stories high. Not to mention extremely expensive. Lasers are already pretty energy consuming, and considering you need them on for long times for one shot, that fucks up your overall energy efficiencies.
- Replacing the pallet. The inside of the vacuum chamber becomes radioactive from the gold pallet causes the vacuum chamber to become radioactive. This isn't a problem now, since there is a few months between full power shots anyway, but if you want to every few seconds that IS a problem. And there is the issue that the evaporated gold ruins your vacuum, and deposits on the chamber. The pallet is also fairly expensive to build (~tens of thousands USD) although that will drop with mass production, but the gold it requires will never make them really cheap.
- Getting energy out. To get energy out, you'd want something around it to absorb the energy, but since you have to get laser power in from all sides, simultaneously, you can't.
- Scaling. You can't just make the pellets bigger. If they get bigger, uniformity of the laser and X-ray power is harder to achieve, and the pressure in the droplet decreases, decreasing the fusion process. But I might be wrong on that.

Overall the system is designed to get high energies in small confined spaces. This is useful for elementary research, and for weapon research. It can be used to simulate the effects of hydrogen bombs, which is very useful since testing them for real is banned. You are aware where the funding of NIF came from? Hint: it's not an energy-production fund.

Maybe some, or even all of these problems can be solved at some point, but it's not very likely and especially not any time soon.



So why do I think that magnetically confined fusion is a more likely option, especially in the short term?

Mostly because it's far closer. It's tricky to confine a plasma, but it is shown to be manageable. Ways to get energy in and out have been tested and designed and are feasible, which has yet to be shown for laser ignition. Efficiencies also increase with size (opposite for laser ignition). The outlines for a blueprint of a commercial plant have been made. ITER will provide a wealth of information about containing and controlling bigger fusion reactions and testing materials (to withstand neutron bombardments), which can then be incorporated in the demonstration model of a commercial plant. This is already mapped out and planned (see DEMO). Basically, commercial fusion power generation by magnetic confinement is two generations away, three to actual use. Commercial fusion power generation by laser ignition, well, we don't even know how far it is away, nor are there any concrete plans for it as far as I know. It's still very much in the initial research stage. Maybe this type of fusion power source will become feasible, and more efficient or cheaper than magnetic confinement, but I can assure you it won't be the first one to be built commercially, unless something very unexpected happens.


Hope you can read this as a substantial opinion, based on facts, and not as a knee jerk reaction to your post. Or superpatriotism or whatever. You could maybe 'expect' me to turn it around, but let's face it, you are defending this NIF thing more than you should, really. By the way, I don't have sources for this beyond a reader that isn't online and a chat with a professor and a post-doc (who actually worked at NIF...) who are both working in the field.

By the way, HiPER aims for a kJ input but an output similar to NIF, which would make it more efficient. Not surprising, since they use a different process that builds on knowledge gained by, among others, the NIF. I mean, comon, it's in the first paragraph on wikipedia: http://en.wikipedia.org/wiki/HiPER