字幕表 動画を再生する 英語字幕をプリント For centuries man has looked to the stars for answers to its most pressing dilemmas. Just as curious ancient societies once sought to learn the future from the heavens, so do today's nuclear physicists. Some believe that nuclear fusion, or the process that stars including our sun use to produce energy, may provide an alternative to current limited energy sources. A global collaboration was formed consisting of the U.S., the European Union, Japan, Russia, China, India, and South Korea. Member nations are building a prototype fusion power plant known as a ITER, which is latin for "the way". The objective is to understand the properties of matter undergoing intense fusion reactions and to serve as a test bed for future fusion power producing reactors. Inside the tomamak, high powered radio waves at several frequencies and highly energetic beams of neutral atoms will heat and control the plasma, or the fuel, in the reaction process. The plasma is an ionized gas made up of the hydrogen isotopes deuterium and tritium that will eventually reach one hundred fifty million degrees. After the plasma has reached a sufficient density, it is further heated by injecting extremely high velocity neutral deuterium atoms. These charged particles are confined by the magnetic field and their density continues to build over time. As the beam particles collide with the lower energy plasma particles they transfer energy to the plasma thereby heating it and driving current. Once in operation, ITER will serve as a working laboratory in which scientists can test the various components of the design and further refine fusion energy so that it might one day provide the world with a clean virtually limitless energy source.