Warmer than the sun

1994/02/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Energia

On December 9 of last year, at 11 and 15 noon, the highest temperature in the history of the Solar System was reached in the North American New Jersey. In his Princenton plasma research laboratory, the fusion reactor called Tokamas, raised its temperature to one hundred million degrees, which is triple the temperature of the Sun in the nucleus. Thus, fused with 30 grams of gaseous tritium deuterium, helium nuclei were formed.

The nuclear reaction was carried out in four seconds and in it an energy of three million watts was released. Until then the mark with 1.7 million watts was the British reactor JET of Culham.

It has been an important step on the road to thermonuclear fusion and has served to encourage scientists. The fusion has important advantages in terms of radioactive waste and fuels. The fuel is very cheap because water is used. More specifically, it uses hydrogen or its diuterio and its tritial isotopes.

However, the path of fusion remains long, since the reactor must be provided with an energy eight times greater than that obtained by fusion.

There are two ways to obtain nuclear energy. One is the rupture of a heavy atomic nucleus (normally uranium), the fission nucleus. The other way is to join two light cores and form one larger, nuclear fusion. The Sun (and the rest of the stars) emits heat through the fusion reactions that are inside.

The fission process is directed and dominates with relative ease in conventional nuclear power plants, but the fusion process presents serious technical difficulties that have not yet been overcome. The difficulty is to unite two positively charged cores, because the cores are not attracted and modified. The nuclear binding technique used in tokama-type reactors is based on very strong magnetic fields.

The Pricenton team expects to get 10 million watts of fusion energy in short, but the most optimistic do not expect the industrial fusion reactor to run before the remaining forty years.