Nuclear Fusion

          The combination of two or more light nuclei to form a heavy nucleus with enormous amount of energy is called the nuclear fusion reaction. This process release energy because total mass of resulting single nucleus is less than the mass of two original nucleus.  

                    Fusion requires extremely high temperature and high pressure just at sun where temperature is millions of degrees Celsius. This is because the small nuclei require enough KE to overcome their electrostatic repulsion. Fusion reactions are responsible for the energy of the sun and other stars. Researchers are interested in Deuterium-Tritium (DT) fusion reaction. In the process, it releases much more energy than normal fusion reaction. Future Fusion power plant such as tokamak or stellarator would generate power for our use using DT reaction. Researchers focus on DT reaction because it generate more power and occur at low temperature than other elements.

          For example, the fusion of two deuterium nuclei into helium is expressed as

₁H² + ₁H² → ₂He⁴ + Energy

CALCULATING  ENERGY RELEASED BY FUSION

Calculate the energy released in the above fusion reaction.

Given Mass of ₁H² = 2.014102 u, Mass of ₂He⁴ = 4.002604 u

Solution

The initial mass of two deuterium atoms = (2 × 2.014102 u ) = 4.028204 u.

The mass lost Δm = (4.028204 - 4.002604) = 0.025600 u

so the energy released is E = 0.025600 × 931 MeV = 23.84 MeV

[1 MeV = 1.6×10^-13 J]

E = 23.84 × 1.6×10^-13 J = 38.144 ×10^-13 J