DOE-HDBK-1019/1-93
Reactor Theory (Neutron Characteristics)
NUCLEAR CROSS SECTIONS AND NEUTRON FLUX
Rev. 0
Page 5
NP-02
NUCLEAR CROSS SECTIONS AND NEUTRON FLUX
To determine the frequency of neutron interactions, it is necessary to describe the
availability of neutrons to cause interaction and the probability of a neutron
interacting with material. The availability of neutrons and the probability of
interaction are quantified by the neutron flux and nuclear cross section.
EO 2.1
DEFINE the following terms:
a.
Atom density
d.
Barn
b.
Neutron flux
e.
Macroscopic cross section
c.
Microscopic cross section
f.
Mean free path
EO 2.2
EXPRESS macroscopic cross section in terms of microscopic cross
section.
EO 2.3
DESCRIBE how the absorption cross section of typical nuclides
varies with neutron energy at energies below the resonance
absorption region.
EO 2.4
DESCRIBE the cause of resonance absorption in terms of nuclear
energy levels.
EO 2.5
DESCRIBE the energy dependence of resonance absorption peaks
for typical light and heavy nuclei.
EO 2.6
EXPRESS mean free path in terms of macroscopic cross section.
EO 2.7
Given the number densities (or total density and component
fractions) and microscopic cross sections of components,
CALCULATE the macroscopic cross section for a mixture.
EO 2.8
CALCULATE a macroscopic cross section given a material density,
atomic mass, and microscopic cross section.
EO 2.9
EXPLAIN neutron shadowing or self-shielding.
