Page 42 - bukuneutron

Figure 2.3: Illustration showing the neutron gauge ap-
plemented in neutron back-scattered technique during
inspection of the hydrocarbon layers in the storage tank

bon materials. Concentration of hydrogen within the
layer is similar therefore gives significant effect on the
neutron scattering. In this situation, the scattering is
almost constant. However, the situation is changed
when approaching the border of each layer where the
concentration of hydrocarbon has some differences.
Large number of neutron would not scatter when pene-
trating the low concentration region. While, large num-
ber of neutron will scatter by the material within the
high concentration region. This will result in low and
high neutron counts by the detector of back-scattered
gauge. The profile of neutron count is illustrated in Fig-
ure 2.4. High and low profile of back-scatter neutron
count indicates the thickness of each layer. Since the
tank radius is known, therefore, for a measured thick-

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