building a star in the comfort of your lab

October 16, 2009

Despite the constant grumbling of naysayers, tiny budgets and disappointment from impatient media outlets, fusion researchers haven’t given up. Igniting a self-sustaining fusion reaction that produces at least ten times the power that was put into it may be an extremely challenging task, but the rewards would simply be too big to ignore. Today, the next big attempt to kick fusion into high gear is the ITER reactor being assembled by a team of scientists and engineers in the south of France. While other researchers have been focused on a reliable, effective method of ignition, the ITER team is aiming far higher. Their goal is to make fusion industrially viable and provide an effective proof of concept test for utility companies interested in building their own artificial sun.

plasma ball

Theoretically, fusion is much more energetic than nuclear fission being used across the world today and it’s a lot safer. It produces little waste which decays relatively quickly and a fusion reactor can’t melt down because as soon as the temperature drops even a notch below insanely blistering, the process winds down unlike the runaway chain reactions possible with fission. Of course, to contain the kind of ferocious reactions produced by nuclear fusion can strip away the lining of the reactor and searing hot plasma that would register at around 150 million degrees (at this temperature the measurement system is pretty much irrelevant) would need to be cooled to remove helium and other byproducts to keep the reaction going. The materials needed to build the reaction chamber and its supporting components? Stainless steel, beryllium, tungsten and carbon fiber. And of course there have to be enough magnets to keep a firm grip on the device’s churning innards.

Now, you can already hear the skeptics. The project will cost billions of dollars, it will only be done by 2018 or so, fusion power has been promised for more than half a century now and we’re still a long ways away. All the same criticisms leveled at countless complex and time consuming projects. And they are valid to a degree. If you’re going to promise something to the public, don’t look to become a media darling and make claims that you can’t back up in reality. If you’re going to take on a challenging project, make good use of your money. But at the same time, what the skeptics need to realize here is that replicating what happens in the core of a star isn’t exactly like boiling an egg. High energy physics aren’t mastered overnight and if you really want to make a machine that can do spectacular things, it will take time and money. Nature doesn’t give you anything for free. You have to work for it.

The $10 billion being allotted for ITER is not even a drop in the bucket when it comes to the kinds of subsidies and credits oil companies and existing utility providers will get on a regular basis. If we allow even less money and demand that scientists somehow cough up new a working fusion reactor, it’ll take even longer to fulfill the stated goal. When it comes to radical new technologies that push our technology to the limits, it’s a question of how badly we want it, how much effort we’re willing invest and how patient we want to be. And right now, as far as fusion is concerned, our lack of will and determination is disturbingly glaring.

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  • Polywell Fusion Reactor experiments.

  • Pierce R. Butler

    … a fusion reactor can’t melt down …

    Yabbut there is that potentially embarrassing Ka-BOOOM!!! problem.

  • Greg Fish

    “… potentially embarrassing Ka-BOOOM!!! problem.”

    Fusion reactors can’t blow up like a nuke. In thermonuclear weapons, a fission device is used to ignite substantial quantities of deuterium and tritium very quickly and violently, with no regard for the efficiency of the reaction.

    Controlled fusion reactions work on slightly different principles and lacking an ignition as powerful as another nuclear bomb, making it go boom would be rather difficult to say the least.

  • Pierce R. Butler

    … making it go boom would be rather difficult …

    Last I heard, the fine art of nuclear fusion requires maintaining a continuous explosion, held a bit below the containment capacity of one king-hell pressure cooker. It’s rather like riding a motorcycle along the edge of a cliff: minor bruises and chagrin if you fall over on one side, but qualitatively different the other way.

    Perhaps the proposed engineering has become rather more fail-safe since I read up on all this, but I’d still vote for keeping the “tame” H-bomb approach on the drawing boards until we’ve totally exhausted all the Amory Lovins approaches.

  • Greg Fish

    Fusion reactors like the ITER tokamak heat up tritium and deuterium to an absolutely hellish temperature of 150 million K and use the sheer heat to combine them into helium. An explosion is a sudden release of energy rather than a roasting oven, so the current idea behind fusion reactors just can’t qualify as explosive in any way.

    You might be thinking of Z-pinch machines, but those are more for igniting fusion and studying extreme environments rather than creating a long term sustainable reaction.

    However… I once read about a crazy idea of detonating thermonuclear warheads in a huge underground bunker where their energy would be absorbed by giant, moving plates kicked back by the blast wave. And as you can probably imagine, that idea was abandoned about as quickly as it was brought up.

  • Pierce R. Butler

    Thanks for the clarification. I still wouldn’t want to be in the neighborhood when a 150MK hose pops, but the global consequences would be a few orders of magnitude less irritating.

    As for the H-Bomb internal combustion device, that sounds an awful lot like Freeman Dyson’s plan for nuclear spaceship propulsion. Poul Anderson wrote a story (Orion Shall Rise, I think), in which such a craft performed derring-do in the Earth’s atmosphere; the thought alone is enough to turn any less of a technophile into a honey-&-locust munching Luddite.

  • JM

    I still say it’s do-able, give or take a few trillion dollars.( A few less wars would help) And that price will come down. What’s the alternative? Dumping radioactive sludge into our ecosystem for 1000’s of years. And in who’s back yard? What’s the cost comparative safeguarding these volatile toxins for eons?

  • JM

    Talking about dollars and cents. Here’s a link to the latest numbers crunch on Nuclear waste disposal.