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1.4 Production of neutron

Production of neutron is the ejection process of neu-
tron from the nucleons in the nucleus of the atom. There
are some potential in between the nucleon and nu-
cleus keeps neutrons inside the nucleon. Therefore,
the external energy which is higher than the internal
potential energy is required to force neutron get out
from the nucleon and nucleus. The methods usually
used to eject the neutron from nucleon and nucleus
are, fission, fussion and spallation.

1.4.1 Spontaneous Fission

Typical example of neutron resulting from spontaneous
process is californium-252 (Cf-252).Cf-252 and all other
spontaneous fission neutron sources are produced by
irradiating uranium or another transuranic element in
a nuclear reactor, where neutrons are absorbed in the
starting material and its subsequent reaction products,
transmuting the starting material into the SF isotope.Half
life of Cf-252 is 2.6 years. Sealed-source of Cf-252
usually has fast neutron with the flux around 107 to
109 ncm2s–1.Thermal neutron can be obtained by let-
ting fast neutron from Cf-252 sealed source passed
through the moderator such as polyethylene material.

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