Class 10 > Unit # 20:Nuclear Structure > Nuclear Fusion

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Explain Nuclear Fusion Reaction and Thermonuclear Energy

Nuclear Fusion Reaction

"A process in which two light nuclei combine (or fuse together) to form a heavier nucleus and energy is released is called nuclear fusion."

The energy released during this process is referred to as Thermonuclear Fusion Energy.

Explanation

When light nuclei of hydrogen are combined to form a heavier nucleus of helium, a tremendous amount of energy is liberated. The final mass of the product nucleus is slightly smaller than the sum of the initial masses (mass defect), and this mass deficit per nucleon is comparatively greater than that in nuclear fission, releasing immense power.

Challenges in Producing Fusion

It is extremely difficult to initiate and sustain a fusion reaction. Because two positively charged nuclei must be brought extremely close together to fuse, work has to be done against the strong electrostatic force of repulsion between them. Overcoming this repulsive barrier requires an exceptionally high thermal energy or temperature.

Raw Materials

Fusion reactions can produce massive amounts of clean energy. The primary raw material for fusion is deuterium ($_1^2\text{H}$), which is found in abundance worldwide in the world's oceans as heavy water.

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Fig: Nuclear fusion of deuterium and tritium nuclei overcoming electrostatic repulsion to form helium and release thermonuclear energy.

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