Page 32 - bukuneutron

neutron capture cross sections. These materials are
suitable to be used for neutron shielding since they
can absorb thermal neutron. The plastic-composite
consist of these materials with hydrogenous polymer
chain is usually made for shielding of neutron.

A draw back from using those materials with high
neutron capture cross section is they will associate with
accompanying radiation. Lithium and cadmium are good
for stopping neutron however the accompanying with
high energy gamma radiation. This require additional
shield to attenuate gamma rays. Boron also has ac-
companying gamma radiation upong activated with neu-
tron, but very much less gamma energy. This makes
boron is used very often in neutron shields. The ad-
vantageous of boron use for neutron shielding is a boric
acid can easily soluble in water and also well bind with
the molecules in polymer chains. The amount of 5% to
10% of boron composited with high density polyethy-
lene are sufficient to shield neutrons. Many high den-
sity PE with some amount of boron is commercially
available for neutron shielding application.

As previously mentioned, water is also possible ma-
terial for neutron shielding since its contain large hy-
drogen atom. However, shaping water to a design form
is difficult and it should be contain in the container.
Nuclear reactor usually use water to moderate as well
shield neutron from a reactor core.Thin water is inef-
fective of neutron shielding therefore, to be used for

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