Page 37 - bukuneutron

the material, some thermal neutron has adsorbed and
the rest will scatter back after collision with the nucleus
in the materials with a large value of the neutron cross
section. Amount of neutron scattered is depending on
the value of neutron cross-section of target materials.
Material has larger neutron cross section would scat-
ter more as compared with the materials will a smaller
neutron cross section value. Variation in amount of
detected back-scatter neutron shows the different ca-
pability of materials to scatter thermal neutron. For ex-
ample, in the case of oil stored in the storage tank,
where there are some layers consists of oil, oil sludge
and water. The oil sludge will scatter larger amount of
neutrons compared with the water since the amount of
hydrogen atom in the oil sludge is larger compared with
water. Based on similar principle, there are have been
developed several neutron back-scattered techniques
utilise in the oil and gas industries.

2.2 Gauge design

In general, gauge is used in neutron back-scattered
technique. It’s consists of appropriate neutron sealed
source and neutron detector which are placed in the
container shielding. In this case, detector is fully iso-
lated from the direct beam of neutron. Some opening
is made on the container shielding for collimation of
scattered neutron to the detector. The detetor is cou-

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