The Fusion Process
While
fission is the process of an atom splitting into two smaller atoms,
fusion is the opposite. Two smaller atoms are fused together to
create a larger atom, also releasing enormous amounts of energy.
Energy is given to the reaction so that the positively charged atoms
can overcome the repulsive force the atoms naturally exert on each
other, thus fusing together. An example of a fusion reaction is the
one that takes place in the sun, where four hydrogen atoms are fused
together to form a helium nucleus and two positrons. This reaction
produces 24.7 MeV of energy. On earth however, the reaction that
will most likely be used in the first fusion reactor is the fusion
of deuterium and tritium to form helium and a neutron. However, the
earth does not have the availability of extremely high temperatures
such as the sun, that allow the fusion reaction to so easily take
place in the sun. The deuterium-tritium reaction requires a
temperature greater than 100,000,000 K to provide the required heat
energy for the two atoms to overcome their repulsive forces. In
addition to achieving the required temperature, the plasma that is
created must also be kept together at that temperature long enough
to produce more useful energy than was needed to produce the
temperature initially.[2] The ongoing
research into fusion is very important, since the fuels used in
fission will get harder to find, while deuterium and tritium are
comparatively much easier to obtain.
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