Thursday, March 16, 2006

What 3 billion degrees means

So a few days ago, the Sandia National Labratories' "Z machine" achieved a pretty spectacular milestone - they generated a plasma that reached 3 billion degrees fahrenheit, or 2 billion kelvins. Hot stuff, coming through!

Aside from the pure scientific value, this is interesting because it is quite a bit higher than necessary for hydrogen-boron (pB11) fusion. I've written about Focus Fusion before, who are just one of a couple of competing groups working on pB11 fusion. I've avoided writing about them too avidly, because of the snake oil potential.

In any case, the people at Focus Fusion have a message reacting to the news from Sandia:
The Sandia machine could potentially be used to burn pB11 fuel, if a pellet containing the fuel were placed at the center of the array. However, there are serious obstacles to a Z-Pinch being used as a practical fusion reactor. For one thing, the giga-gauss fields needed for generating practical amounts of fusion energy are not achievable with the Z-Pinch unless it can be used to form plasmoids. Second, the Z-Pinch destroys the electrodes with each shot, so rapid pulsed operation is precluded.

The Sandia result does confirm two important conclusions of focus fusion research — that high ion temperature can be obtained from a pinch machine, and that huge differences between ion and electron temperatures are possible.
The focus fusion website is full of all sorts of wonderful promises - cheap, limitless energy from seawater for example. I want to believe, I really do. If nothing else, if we're going to avoid an environmental calamity we need a technology that can make coal obsolete for electrical generation. The Focus Fusion site claims a potential capital cost per watt of about 3-6 cents per watt, which would make it an order of magnitude cheaper than coal.

Even if fusion doesn't give us the energy we need to desalinate the Indian Ocean and irrigate the Sahara (ambitious, much?) something that can keep China and India from building their economies on coal will do quite enough, thank you very much.

Of course, a cheaper supply of electrical energy would also make yesterday's plasma/FT ethanol process more economical.

And yes, I would absolutely favour nuclear fusion as an alternative to coal, oil, gas, and conventional nuclear if it were anneutronic (radiation free.) Hell, if Focus Fusion delivers, I'd prefer it to wind and solar!

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