Monday, April 3, 2006

Messenger Purse Indie

With u. .. "Fusion"?

We will continue with the series of nuclear power that started the last day . After

understand what nuclear fission in the previous chapter we now with an even more entertaining and exciting: the nuclear fusion.

Despite having a name so similar, fission and fusion are actually antonyms.
We discussed that fission is roughly into "atoms break." Well, the merger is "paste atoms."

is taking two small atoms and merge them into one heavier. Upon this reaction, releasing large amounts of energy. Surely you have heard many say that even we do not use energy from nuclear fusion. Well, actually this is completely false . Let no one take your hands to the head, it is true that still is being tested in large reactors (eg ITER ) the feasibility of this energy source. Yet we use more energy from fusion reactions than any other type. Our self-centeredness leads us to believe that only use the energy that we release, but what about the sun? The Sun
fusion reactions occur continuously, hence comes all the energy we receive from our star. How are these reactions?

Let's start by seeing how an atom.
We saw that an atom has electrons in the crust and protons and neutrons in the nucleus. As protons and electrons have the same charge but opposite sign (positive protons and negative electrons), so that the burden of an atom is neutral there must be the same number of both. The number of protons or electrons is called the atomic number ( Z) and determines which element we have. So if we see that an atom has one proton and one electron, ie, if Z = 1, we are faced with a hydrogen atom. If Z = 8 is oxygen, if Z = 92 have uranium, which we raised in the previous article, etc.

As we have seen is the number of protons (qe is equal to the electron if the atom has no net charge) determines which type of atom we have.
What if we add neutrons? We do not all you want, but in principle we can. Such as protons those who say what is atom by adding neutrons the atom will remain the same, but it will be a " isotope " different.

For example, the hydrogen in a lifetime, which is usually water along with oxygen, has one proton, an electron and no neutrons. But there is more isotopes of hydrogen: we can stick a neutron and then call deuterium (H 2) or two neutrons and tritium will then be ( 3 H). The water formed with hydrogen, one of these two isotopes is called heavy water , certainly more than one sounds.

Now that we are experts in nuclear physics we can see what happens in the sun a star
Inside there are huge amounts of hydrogen, both of which we call normal, as the other two. Then when they
conditions too extreme pressure and temperature, the following reaction occurs:

2 3 H + H -> 4 He + n + 17.6 MeV

" Send "? This means that an atom of deuterium is fused with another of tritium and then transforms into an atom of helium (which is the name of atom with two protons and an unbeatable element when we make our voice sounds a whistle). It also appears that a neutron "spare" and about 18 MeV of energy.
Finally! That's the energy that we toast when we go to the beach and basically without it life on Earth would be impossible.


usually underestimate the energy from the sun, but if you take all the energy that comes in a day and concentrate our at a single point of Earth, would be released so much energy that the Earth would break literally two , and that with the energy of a single day ...

But why on Earth we are unable to fuse atoms as if they were clay pellets? Precisely because of the extreme conditions we were talking about: you can not put two atoms of hydrogen in a darkened room and a slow song and expect them to merge, that only works with people;)
There are different techniques to achieve in the laboratory and many of them are very promising, but today we can not guarantee anything.

But supposing, which is functioning, and hopefully not too distant, we found an energy source that meets the two conditions we talked about:
stupidity There is a raw material (in the sea there is plenty of water and water is much hydrogen, and it is extremely difficult to find deuterium) and will not produce hazardous waste and possible accidents in reactors would not be catastrophic for the environment: it is a clean energy source .
the other hand is a source that releases a lot of energy. At first glance the 18 Mev for reaction are quite short compared with 200 of the fission reactions, but we must bear in mind that the hydrogen atoms are much smaller than those of uranium, and they are much more abundant, we a source that releases large amounts of energy .

Now we only have to pray, digooo, experience, and we will have solved one of the major problems of XXI century humanity ...

0 comments:

Post a Comment