Nuclear fusion

Currently all commercial nuclear reactors are based on nuclear fission. But there is
another possibility of nuclear energy generation by a safer process called nuclear
fusion. Fusion means joining lighter nuclei to make a heavier nucleus, most commonly
hydrogen or hydrogen isotopes to create helium, such as
2H + 2H → 3He (+ n)
It releases a tremendous amount of energy, according to the Einstein equation, as
the mass of the product is little less than the sum of the masses of the original individual
nuclei.
Such nuclear fusion reactions are the source of energy in the Sun and other stars. It
takes considerable energy to force the nuclei to fuse. The conditions needed for this
process are extreme – millions of degrees of temperature and millions of pascals of
pressure.
The hydrogen bomb is based on thermonuclear fusion reaction. A nuclear bomb based
on the fission of uranium or plutonium is placed at the core of the hydrogen bomb.
This nuclear bomb is embedded in a substance which contains deuterium and lithium.
When the nuclear bomb (based on fission) is detonated, the temperature of this substance
is raised to 107 K in a few microseconds. The high temperature generates sufficient
energy for the light nuclei to fuse and a devastating amount of energy is released.