The Yomiuri Shimbun
The Japan Atomic Energy Agency announced Tuesday that its JT-60 tokamak had extended its plasma duration time to 28.6 seconds, smashing the world record of 16.5 seconds it achieved in 2004, an achievement that bodes well for the future of fusion energy.
As part of an international project, Japan, European countries and the United States are expected to construct the ITER (International Thermonuclear Experimental Reactor) in France by 2015. The goal is a plasma fusion reaction of more than 400 seconds, which would create 10 times more energy than that used to heat atoms in the experiment.
Because the latest JT-60 test nearly doubled the former record, it is thought likely the ITER will meet its target as it has the same basic structure as the JT-60.
Plasma duration time is a fusion energy realization indicator.
The JAEA used new parts in the JT-60, having improved its capability to hold the plasma in its powerful toroidal magnetic field.
Plasma is an ionized gas composed of free-floating ions, electrons and neutral particles.
While substances change state from solid to liquid to gas as temperatures rise, at very high temperatures atoms are transformed into plasma, composed of ions and electrons. A plasma is considered a state of matter distinct from solid, liquid or gas.
One gram of deuterium (also known as heavy hydrogen) and tritium in a plasma state leads to nuclear fusion, and is expected to produce as much energy as eight tons of petroleum. |