Fission

1
Fission

• Lise Meitner- Austrian physicist during time of
  WWII.
• Discovered that bombardment of uranium with
  neutrons can split the nucleus into two pieces.
• Fission- (splitting) the splitting of an atomic
  nucleus into two or more large fragments.

2
Fission

• Fission of one nucleus often leads to fission of
  another nucleus, since neutrons are emitted in
  the process.
• Thus nuclear reactions are often chain reactions
  .
• If rate of reaction is controlled, this energy
  can be used to heat materials and do useful work.

3
Nuclear Fusion-

• When two or more nuclei combine to form a larger
  nucleus.
• This is the nuclear process which produces energy
  in stars (ex the sun).
• Most typical solar reaction 2
  hydrogen nuclei fuse to form helium.
• This is the energy source that sustains life on
  earth.

4
Fusion reaction

• There are 2 isotopes normally involved in
  hydrogen fusion
• Deuterium (mass 2) and
• tritium (mass3)
• What is the nuclear notation for these 2 isotopes?

5
Some advantages in utilizing fusion reactions

1. The fusion of hydrogen produces 20 times the
   energy produced by the fission of an equal mass
   of uranium.
2. Deuterium is abundant on earth.
3. No radioactive products produced.
4. Reactions are easier to control than fission
   reactions.

6
Problems with Fusion Reactions

• Enormous pressures and temperatures are required
  for the reaction to take place (on Earth, a
  temperature of 200 billion Kelvin).
• There arent any materials that would contain
  this type of reaction.