Nuclear Fusion :-
It is a nuclear process in which two light (small) nuclei fuse to form a larger nucleus, energy is released.
₁H¹ + ₁H¹ → ₁H² + e⁺ + v + 0·42 MeV
₁H² + ₁H² → ₂He³ + n + 3·27 MeV
₁H² + ₁H² → ₁H³ + ₁H¹ + 4·03 MeV
- When fusion is achieved by raising the temperature of the system so that particles have enough kinetic energy to overcome the coulomb repulsive behaviour. It is called thermonuclear fusion.
- Thermonuclear fusion is the source of energy output in the interior of stars.
- The fusion reaction in the sun is a multi-step process in which the hydrogen is burned into helium. Thus the fuel in the sun is the hydrogen in its core.
Four hydrogen atoms combine to form and helium atom with a release of 26.7 MeV of energy.
i.e. 4 ₁H¹ + 2e⁻ → ₂He⁴ + 2V + 2y +26·7 MeV
- The age of the sun is about 5 x 10⁹ years, it is estimated that there is enough hydrogen in the sun to keep it going for another 5 billion years.
- Hydrogen bomb working on the principle of nuclear fusion. It is more powerful and dangerous than the nuclear fission that i. e. 1000 times.