Fission And Fusion

Nuclear energy can also be released by fusion of two light elements (elements with low atomic numbers). The power that fuels the sun and the stars is nuclear fusion. Unlike nuclear fission, there is no limit on the amount of the fusion that can occur.

Fission and Fusion

Nuclear Fission

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Nuclear Fusion

Why Uranium and Plutonium?

the instability of radioactive isotopes

An atom of a radioactive isotope will spontaneously decay into another element through one of three common processes: Alpha decay Beta decay Spontaneous fission In the process, four different kinds of radioactive rays are produced: Alpha rays, Beta rays, Gamma rays, Neutron rays (3).

When a nucleus fissions, it splits into several smaller fragments. These fragments, or fission products, are about equal to half the original mass. Two or three neutrons are also emitted.

Both fission and fusion are nuclear reactions that produce energy, but the applications are not the same. Fission is the splitting of a heavy, unstable nucleus into two lighter nuclei, and fusion is the process where two light nuclei combine together releasing vast amounts of energy. Fission is used in nuclear power reactors since it can be controlled, while fusion is not utilized to produce power since the reaction is not easily controlled and is expensive to create the needed conditions for a fusion reaction.

Scientists knew that the most common isotope, uranium 238, was not suitable for a nuclear weapon. There is a fairly high probability that an incident neutron would be captured to form uranium 239 instead of causing a fission. However, uranium 235 has a high fission probability.

Difference between fission and fusion

Nuclear Chain ReactionsA chain reaction refers to a process in which neutrons released in fission produce an additional fission in at least one further nucleus. This nucleus in turn produces neutrons, and the process repeats.

http://www.atomicarchive.com/Fission/Fission2.shtml