From: "Oliver Keating" <oliver.keating@NOSPAMPLEASE.ic.ac.uk>
Newsgroups: sci.physics.plasma
References: <cnb87u$e11$1@saturn.cs.uml.edu>
Subject: Re: ITER - reactor
Date: Wed, 29 Dec 2004 12:16:12 -0000
Organization: Customer of PlusNet plc (http://www.plus.net)
"Lubos Motl" <motl@feynman.harvard.edu> wrote in message
news:cnb87u$e11$1@saturn.cs.uml.edu...
>
> Hi!
>
> Does anyone know how big chance there is that ITER will work? What are the
> main problems with the project right now?
>
> http://motls.blogspot.com/2004/11/fusion-reactor-iter.html
>
> Please send your answer to your e-mail, or post it to my blog. Thanks.
>
> Best wishes
> Lubos
> ______________________________________________________________________________
> E-mail: lumo@matfyz.cz fax: 617/496-0110 Web:
> http://lumo.matfyz.cz/
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> (call)
> Webs: http://schwinger.harvard.edu/~motl/ http://motls.blogspot.com/
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I work at the Culham Science Center, England. We have two machines, one
called "MAST" and one called "JET". Fusion works, that has been
demonstrated, particularly on JET, where a power of 17MW of fusion has been
demonstrated. The problem is, that to run JET along with all of its
associated components takes nearly 1GW of electrical power to run it up. In
fact so much that the energy has to be stored on site by way of two
enourmous 400 ton spinning machines, to even the load on the power grid.
ITER has a couple of main advantages over JET - it is bigger. Arguably the
main barrier to fusion is turblence, this transports the heat and energy out
of the plasma quickly, but if you make the plasma very big, it takes longer
and therefore you get better results. The problem is a bigger machine is
much more expensive, but fusion power certainly seems to suit economies of
scale quite well, unlike what "spiderman2" would have you believe. Secondly
ITER will use superconducting field coils. The intense magnetic field
required to contain the plasma has to be generated by driving several
millions of amps of current around coils. A high school physicist will tell
you the power lost goes like current squared, so superconding coils will
greatly cut down the power requirements of ITER, and move us a bit closer to
the goal of producing a machine that can make more power from fusion than
the power it takes to run it!
The question is not whether ITER will "work", the question is how well will
it work. It is hoped it will provide 500MW of power (not to be turned into
electricity) and have a plasma for several minutes at a time. Many
theoretical work has been done, this machine costs 5 billion dollars, no one
wants it to be a white elephant. The only thing to do now is build it and
see what happens, if the predictions are right, and begin on some of the
other technological and scientific challenges in fusion, such as materials.
I think people under-estimate the importance of the fusion project. This
really is the only geniune alternative to fossil fuel production, and unlike
solar or wind power, can easily provide the "base load" and doesn't take up
any more space than a conventional power plant.