Posted on 08/06/2002 9:04:15 PM PDT by Brett66
Fusion reactor breaks duration record
10:50 06 August 02
NewScientist.com news service
A powerful plasma discharge has operated for a world record 210 seconds in an experimental French fusion reactor. The demonstration is a significant step toward the long plasma confinement times needed in a practical fusion reactor.
Physicists sustained the three-megawatt electric discharge in the Tore Supra reactor at the Association Euratom-CEA in Cadarache. During that interval, it dissipated more than 600 megajoules of energy, more than twice the previous record, also set by Tore Supra in 1996.
The record was broken thanks to an upgrade that added active cooling to the tokamak, the reaction vessel. The experiment was also the first one to use a series of superconducting coils to generate a strong permanent toroidal magnetic field to contain the plasma. The scientists did not aim to demonstrate nuclear fusion on this occasion.
Operating time has been a key technology limit for fusion, says Federico Casci of the European Fusion Development Agreement office in Garching near Munich, Germany. Previous experiments have heated and compressed nuclear fuel to the point where the nuclei of heavy hydrogen isotopes fuse and release energy. But the confinement times were so brief that the reaction released little energy.
Heat sink
The new test was conducted as part of the planning for ITER, the International Tokamak Engineering Reactor to be built by the European Union, Russia, Japan, and Canada.
"ITER is aiming for half-hour pulses," Casci told New Scientist, so its designers needed to test systems that could efficiently remove the heat energy deposited in the hot plasma. He calls the demonstration "a key piece in the puzzle of building ITER" and hopes further tests will yield even better results.
ITER's planners hope to decide on a site in 2003; candidates are in Japan, France, Spain, and Canada. If all goes to plan, construction will begin in 2005, with operation to start around 2013. The US, which earlier withdrew from ITER, is now considering returning.
Researchers expect ITER to be a significant advance over existing fusion reactors because it promises for the first time to let them study key parameters such as confinement time, temperature, density and pressure all at the same time. The conditions required for fusion are so difficult that existing tokamaks are limited to testing one parameter at a time.
I thought this was rather humerous. Reminds me of a movie where they couldn't get it stopped either.
When you try to play god you had better get it right.
600 megajoules? Wow that's nearly half the energy used by Anna Nicole Smith when she walks 10 feet. Which in her case should be described as "MOOving".
I couldn't figure out why my wife was calling me "fusion reactor" all day. This clears it up.
--Boris
Although the facility is not on American soil, American scientists are well-represented. It is an international effort; each scientist has his own funding sources.
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