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Nuclear Fusion

What is nuclear fusion?

Nuclear fusion is the process where very light nuclei of chemical elements could be joined or fused to form heavier elements by the emission of energy and the loss of mass during the nuclear reactions. For example, if two protons and two neutrons would be fused or two deuterons would be united, the produced energy is very large about 1.2 MeV (megaelectronvolt) in the nuclear fusion process.

Nuclear fusion definition, uses, equation, energy and working process in chemistry

Uses of nuclear fusion

Fusion technology or formula was first initiated in the second World War for the preparation of thermonuclear weapons and hydrogen bombs by nuclear reaction. Today, fusion fuel is used in the nuclear reactor for the electric or nuclear power generation plant in peaceful applications to mankind.

Nuclear fusion in the sun

Nuclear fusion reactions initiated by high temperatures are called thermonuclear reactions of the following type, 41H12He4 + 21e0 + energy. It is believed that the above net fusion or thermonuclear reaction occurs in the interior of the sun or decent star of our solar environment where the temperature is of the order of twenty million-degree Celsius. The calculated energy output during the fusion reaction in sun losing the mass at the rate of four million tons per second. Even with this huge mass loss, our sun will continue to bless us with a good earth solar environment for thirty billion years.

How does nuclear fusion work?

The working process of nuclear fusion for hydrogen bombs has been not reviled. The common fusion process in chemistry or physics involved deuterium or tritium (atomic number =1 and mass number = 2 or 3) by the liberation of huge heat or energy. The energy released in the fusion of nuclei originates from the fact where the loss of mass occurring in the artificial nuclear reaction. Energy release in the nuclear fusion process can be calculated from the mass defect and Einstein’s mass-energy equation.

What is fusion energy?

Nuclear fusion energy is the amount of energy released during the fusion reaction. It can be calculated from the mass defect.  Let us take the nuclear transformation, 21H1 + 20n12He4. The mass defect = (2 × 1.00814) + (2 × 1.00898) – 4.00388 = 0.3424 amu. Therefore energy release during the fusion process = 0.03424 × 931 MeV ≈ 28 MeV, where 1 amu = 931 MeV given from Einstein equation.

Fusion equation Fusion energy
21H22He4 24 MeV
1H3 + 1H22He4 + 0n1 17 MeV
1H3 + 1H12He4 + 0n1 20 MeV
1H3 + 1H22He4 + 20n1 11 MeV

Nuclear fusion and fission

In nuclear fission, a natural particle approaches radioactive uranium-235 without any formation of the repulsive barrier. In nuclear fusion, positively charged particles have approaches to each other by the formation of the repulsive types barrier. Therefore, the approaching nuclei must be supplied with sufficient kinetic energy to overcome the repulsive barrier. To overcome the repulsive barrier in the hydrogen bomb or fusion reactor, we use fission technology in the preliminary step for the initiation of extremely high temperatures or energy.

Stellar energy

In learning chemistry or physics, stellar energy meaning the continuous emission of enormous amounts of energy from the sun and other stars due to the fusion process. The temperature of the interior of the stars is of the order 107 to 108 K. Such temperature was attained during the construction of the original gaseous nebulae. At such high temperatures, the atoms are completely stripped of their electrons. The bare nuclei with extremely high thermal energy fuse together at a rapid rate which is reasonable for the colossal output of energy.

In 1938, Bethe and Weizsacker independently proposed a theory in which 4 helium nucleus is formed in the stars or sun. The fusion of four protons in a series of changes through the isotopes of carbon, nitrogen, and oxygen. The net stellar reaction is, 41H12He4 + 21e0 + energy. This is the main source of stellar energy.