Notes for UPSC-The Nuclear Fission

Nuclear Fission

Nuclear Fission

• Nuclear fission is a reaction in which the nucleus of an atom splits into smaller parts
• Nuclear fission can either release energy or absorb energy: for nuclei lighter than iron fission absorbs energy, while for nuclei heavier than iron it releases energy
• Energy released can be in the form of electromagnetic radiation or kinetic energy
• The amount of free energy contained in nuclear fuel is about a million times that contained in a similar mass of chemical fuel (like petrol)
• The atom bomb or fission bomb is based on nuclear fission
• Example: fission of Uranium-235 to give Barium, Krypton and neutrons

Nuclear Fusion

• Nuclear fusion is the process by which multiple nuclei join together to form a heavier nucleus
• Nuclear fusion can result in either the release or absorption of energy: for nuclei lighter than iron fusion releases energy, while for nuclei heavier than iron it absorbs energy
• Nuclear fusion is the source of energy of stars.
• Nuclear fusion is responsible for the production of all but the lightest elements in the universe. This process is called nucleosynthesis
• Controlled nuclear fusion can result in a thermonuclear explosion – the concept behind the hydrogen bomb
  
• The energy density of nuclear fusion is much greater than that of nuclear fission
  
• Only direct conversion of mass into energy (collision of matter and anti matter) is more energetic than nuclear fusion
• Example: fusion of hydrogen nuclei to form helium