Monday, August 13, 2012

Fusion: The quest to recreate the Sun’s power on Earth.

Cheap energy with a Thermonuclear Reactor. Fusion, many believe, could be the answer. It works by forcing together two types, or isotopes, of hydrogen at such a high temperature that the positively charged atoms are able to overcome their mutual repulsion and fuse. The result of this fusion is an atom of helium plus a highly energetic neutron particle. Physicists aim to capture the energy released by these emitted neutrons, and use it to drive steam turbines and produce electricity.

It's just one of the huge number of challenges facing the designers of this groundbreaking project. The concept was discussed and argued over for several decades before finally being agreed in 2007 as a multinational cooperation between the European Union, China, India, Japan, South Korea, Russia and the US – in total, 34 countries representing more than half of the world's population.


These issues, plus the logistics of dealing with multiple nations with their own fluctuating domestic budget constraints, mean that the site won't be ready for the first experiments until 2020. Even then, they will just be testing the reactor and its equipment. The first proper fusion tests, reacting deuterium (a hydrogen isotope abundant in sea water) and tritium (which will be made from lithium), won't take place until 2028.

Those will be the key tests, though. If all goes to plan, the physicists hope to prove that they can produce ten times as much energy as the experiment requires. The plan is to use 50 megawatts (in heating the plasma and cooling the reactor), and get 500 MW out. Larger tokamaks should, theoretically, be able to deliver an even greater input to output power ratio, in the range of gigawatts.

Source:
http://www.bbc.com/future/story/20120810-the-quest-to-recreate-the-sun/1
http://www.iter.org/

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