Differences between Fission and Fusion
The differences between Fission and Fusion are:
|2. Energy released per fission is about 200 MeV.||2. Energy released per fusion is about 23 MeV.|
|3. No restriction for temperature.||3. High temperature and pressure is needed.|
|4. Produces radiation.||4. Produces no radiation.
|5.It is a single stage reaction.||5.It is a multistage reaction.
|6. Fuel is either in solid or liquid state.||6. Fuel is in plasma state.
|7. E.g. : 0n1 + 92U235→56Ba141 + 36Kr92 + 30n1 + E||
7. E.g. : 1H2 + 1H2→2He4 + Energy
The nuclear fusion process however is not easy to carry out because the nuclei undergoing fusion are positively charged and they would repel each other very strongly. Hence they must be brought very near to each other to overcome this electrostatic force of repulsion so that they come within the range of nuclear force. For this not only a high pressure is necessary but also the kinetic energy of nuclei must have high value of the order of 0.1 MeV. Since the process of nuclear fusion requires a very high temperature, the nuclear fusion reactions are called thermonuclear reactions and the energy released is termed as the thermonuclear energy.
Controlled Thermonuclear Reactions
The uncontrolled fusion reaction (H- bomb) produce large amount of energy in a fraction of second. If this energy can be controlled, it can be used for constructive purpose . As nuclear fusion reaction requires high temperature, the problem for controlled fusion is to produce such high temperature, and to design a container to hold such high temperature gas .