For neutron attenuation calculations, the elastic and inelastic
scattering reactions, and neutron-capture interaction process, are
of great importance (Kaplan, 1989). The effect of the sample can
be described by an equivalent absorption cross-section called an
effective removal cross section (Blizard and Abbott, 1962). The
removal cross-section is the probability that a fast or fission energy
neutron undergoes on first collision, which removes it from
the group of penetrating, uncollided neutrons.