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Construction of French Fusion Reactor Underway
GarryFre writes "It has been said that fusion is 50 years away for quite a few decades, but now work has actually been started. Digging has begun in the south of France on the planned site for France's first fusion reactor. A tokomak is a torus shaped magnetic confinement device which is necessary to withstand the temperatures associated with fusion that are so high, solid materials can't hold them. As such, the building represents the future core of ITER (International Thermonuclear Experimental Reactor.) It will be interesting to see if it takes 50 years to build it."
LE DAILY NEWS
Wednesday, September 15, 2060
The country formerly known as France has successfully performed its first and last Fusion reaction.
It may well be physically in France, I wouldn't call it French per se. The I in the name most assuredly stands for International, with technical and financial input from around the world (China, the EU, India, Japan, Korea, Russia, and the USA, in alphabetical order).
It's a project we all may ultimately depend on as a civilisation, so the International part is important.
We'll do but we'll call it "Freedom Fusion".
"There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed H
the world's first Fusion Reactor
http://en.wikipedia.org/wiki/Farnsworth-Hirsch_Fusor
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
That eternal "Fusion is 50 years away" saying stopped being due to physics and started being due to squabbling countries and their bureaucracies many years ago. ITER could have been started over a decade ago.
Free the Quark 3 from asymptotic confinement! Bring your charm! Don't get down! All colours and flavours welcome!
SPELLING FAIL.
Dog is my co-pilot.
I guess your Free World doesn't have any gypsies in it.
Shame about the whole 3 strikes business and kicking the Roma's out of the country...
People replying to my sig annoy me. That's why I change it all the time.
Design parameters for a fusion reactor:
1. Shielding: 10m of water or similar as well as magnetic shielding
2. Energy density 10kW/m2
3. Politics: Not in my backyard
Conclusion:
Sun
1. Atmosphere and earth magnetic field: perfect
2. perfect almost anywhere
3. 150 million km away: perfect
don't cut it off www.mgmbill.org
Actually, ITER is intended to demonstrate a useful amount of energy production from fusion. It's baseline design is for Q=10, i.e. 10 times more power out from fusion than put in. This is essentially a feasibility demonstration, and experimental test bed for things like wall modules and blankets. The follow-on (DEMO) will then be a prototype power plant, and actually be connected up to generators etc.
ps. though AC, also a plasma physicist working on tokamaks
There are two main reasons why it is thought that ITER can achieve more power out than in (10 times more in fact)
1. It is about 8 times the plasma volume of JET (about 2x in each direction). The temperature gradients in tokamaks have limits (things like Ion Temperature Gradient mode-driven turbulence) so the bigger you make the machine the hotter you can make the middle of the plasma and the better your performance. The problem with this is that the power output goes like the volume, but the area this power is deposited on goes like the area. Hence why small fusion plants would be nice, and materials are the biggest issue for ITER and DEMO
2. They will be using Tritium in ITER. Tokamaks today have only very rarely used tritium (e.g. JET, JT60-U) to produce more power out than in (very briefly 1s). This is because the plasma physics doesn't really change when you add Tritium, so experiments use Deuterium which is much cheaper and less dangerous (e.g. radioactive). At 100 million degrees, the D-D fusion rate is still pretty small and so the amount of fusion energy produced is tiny. The D-T rate is orders of magnitude higher and so significant power can be produced
p.s. Yes, AC plasma physicist
Fortunatly the magnetic confinement techniques they'll be using doesn't fail at any particular temperature. RTFM!
The whole point of ITER was to "demonstrate" that the science is settled. Apparently "the science" is fully settled. Nevertheless they've made several serious design flaws, and are seriously behind schedule (and below expected results for what they've done too). Nevertheless, they're charging ahead, and all smart people hope they succeed.
Btw, there are fusion reactors in most large hospitals, for neutron production. They're called "fusors" and they're basically a rolled up television display. Additionally these (very simple) devices are used for scientific research in most universities. They're very reliable, but have Q levels around 0.1 up to 0.3 for professionally constructed ones.
Imho, I think the American research plan is smarter than the European one. At the very least for the simple fact that Europe is throwing all their eggs in the same (proven to be somewhat unreliable) basket. America may be underfunding fusion research, absolutely, but at least America's underfunding 5 different attempts (including steam-based fusion, my favorite). But there are others, and there are even hybrid machines (meant to do research and to produce fusion, e.g. Z-pinch, or the Z-machine). Also there are several American tokamaks, just in case that's the solution after all.
The tokamak approach banks on pushing back to all forces that act on a fusing plasma, and it's like placing 2000000 small propellors on the ground to control a raging thunderstorm. I'm not saying it will never work, but I'll be utterly amazed. There are other approaches. Hydrogen bombs, on the plus side, they're proven to be effective. On the downside ... well ask some pacific ex-islands ... they know. Then there's inertial confinement fusion, where you generate a number of (relatively) small forces that converge on the same point. For a short time, huge forces will act on this small point, generating fusion. Steam-based fusion is an example, but so is laser fusion, and essentially Z-pinch too. There's also the polywell, an evolution of the only type of fusion rector in commercial use, the fusor, which is a fusor with a magnetic field to replace the fusor grids (google "should google go nuclear ?"). There's even a few attempts that involve principles that boil down to shooting high pressure gas in what's essentially a funnel, resulting in huge pressures just behind the end of the funnel. And I don't really understand how the Z-pinch is supposed to work.
Which is still a tiny bit short of the 100,000,000K that they're looking at. http://en.wikipedia.org/wiki/Iter#Reactor_overview.
The above AC is clearly lying about being a plasma physicist - he probably just read this book over the weekend and now understands everything. Literally.
I went to a talk from a fusion proponent recently who was involved with ITER, and had worked on fusion for most of his career. His view is that the media obsess over break even, and don't understand the reasons they've not hit it. His explanation was that they know how to get to break even now, but that wouldn't make for a usable reactor, as the cost of enegy production would be just too high if you're only just past that threshold. Also the cost of hitting break even now is considerably more than not hitting it. So instead of wasting lots of money hitting break even for a headline, they're trying to sort the issues they know to exist that are stopping them from being considerably more efficient than break even.
There were people on ITER who wanted it to be connected up to the grid, so that if they surpass break even (which they expect to), they'd be able to get a considerable PR coup. Problem is, hooking it up would have added considerably to the costs, which given how much it's overrun could have ended up killing the project.
jh
I said it earlier and I'll say it again: this is *not* a French reactor. It may be physically based in France, but it's an international endeavour. There's already a tokamak in operation, located in England and operated by the whole EC: it's called JET, for "Joint European Torus".