Page 30 - Curriculum Visions Dynamic Book

Fusion: combining atoms
Whereas nuclear fission is splitting the An endless supply of
atom, nuclear fusion forces two atoms to come cheap energy
together, or fuse, to produce an even heavier atom. The fusion of atoms releases huge amounts of energy.
Fusion has proved to be one of the most difficult tasks for scientists to perform, yet
it is one of the commonest features of the Universe. The reason scientists find fusion so difficult is that enormously high temperatures and great pressures are needed to cause the
Scientists know that if they can use the fusion process to make energy, they can use hydrogen from ordinary water (in a form called heavy water). This supply will last for billions of years.
However, because a nuclear reactor can only be a tiny fraction of the size of a star, the size (and gravity) must be compensated for by creating even higher temperatures than
reaction. This commonly happens in the exist in stars. Scientists are
stars. So getting fusion going on Earth is nothing short of making stars!
From hydrogen to helium
The main reaction that occurs inside a star is the fusion of the simplest atom – hydrogen
– into the next simplest atom, helium. This happens under the pressure created by the huge amount of gravity created in a star. Inside
working to solve this problem today, and it is likely they will achieve success by the middle of the twenty-first century.
 The Sun is made mainly of hydrogen. Its immense gravitational power pulls the hydrogen atoms together to form helium. The flow of energy so produced
makes the Sun extremely hot,
and enormous amounts of energy a star atoms are literally pulled together by are released to space. A small
gravity. As they fuse, they release energy, which causes the star to rise in temperature until it may be well over 10 million degrees. This is called a thermonuclear reaction.
Deuterium
 The deuterium-tritium fusion reaction. Deuterium and tritium are isotopes of hydrogen.
fraction of this energy reaches Earth as sunlight, ultraviolet light and infra-red light.
In this way nuclear fusion reactions already make
life on Earth possible.
Helium
Energy
Neutron
Tritium
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