Nuclear Fusion: The Ultimate Source of Energy:

An energy hungry world views with envy the glowing power of  the sun and the stars, which is based on a slightly different nuclear process called nuclear fusion. Nuclear  fusion  takes place when two light atomic nuclei  join  orfitse  together to  form  one nucleus.  . Fig. shows one of  the simplest fusion reactions. TWO  nuclei of heavy hydrogen (deuterium! also fuse to give a nuc!eus  of helium, a neutron and energy. In this process a tremendous amount of energy is released. Half a kilo of deuterium gas would yield as much energy as 1300 tons of coal. What is more, we can get deuterium from sea water.

There's about 40 nlillion tons of deuterium  in sea water. This could provide us energy for many thousand million years. Well then, what stops us from tapping this source of energy? The reason is that high temperature,  equivalent of millions of degrees centrigrade, is required to start fusion. And once the gas has been heated, it must be prevented from expanding;  it must be contained. But no container walls can withstand such temperatures. Hence, entirely new techniques have to be developed. Much activity is going around the world to generate power through nuclear fusion. The development  of fusion power has proved to be, perhaps, the most difficult task ever tackled. Nevertheless,  if fusion reactors come into being, humankind would never again face an energy shortage.