Atomic and Nuclear Physics
DOE-HDBK-1019/1-93
NEUTRON INTERACTIONS
NEUTRON INTERACTIONS
Neutrons can cause many different types of interactions. The neutron may simply
scatter off the nucleus in two different ways, or it may actually be absorbed into
the nucleus. If a neutron is absorbed into the nucleus, it may result in the
emission of a gamma ray or a subatomic particle, or it may cause the nucleus to
fission.
EO 3.1
DESCRIBE the following scattering interactions between a
neutron and a nucleus:
a.
Elastic scattering
b.
Inelastic scattering
EO 3.2
STATE the conservation laws that apply to an elastic collision
between a neutron and a nucleus.
EO 3.3
DESCRIBE the following reactions where a neutron is
absorbed in a nucleus:
a.
Radiative capture
b.
Particle ejection
Scattering
A neutron scattering reaction occurs when a nucleus, after having been struck by a neutron,
emits a single neutron. Despite the fact that the initial and final neutrons do not need to be (and
often are not) the same, the net effect of the reaction is as if the projectile neutron had merely
"bounced off," or scattered from, the nucleus. The two categories of scattering reactions, elastic
and inelastic scattering, are described in the following paragraphs.
Elastic Scattering
In an elastic scattering reaction between a neutron and a target nucleus, there is no energy
transferred into nuclear excitation. Momentum and kinetic energy of the "system" are conserved
although there is usually some transfer of kinetic energy from the neutron to the target nucleus.
The target nucleus gains the amount of kinetic energy that the neutron loses.
Rev. 0
Page 43
NP-01
