A neutron detector has a volume of neutron moderating material and a
plurality of individual neutron sensing elements dispersed at selected
locations throughout the moderator, and particularly arranged so that
some of the detecting elements are closer to the surface of the moderator
assembly and others are more deeply embedded. The arrangement captures
some thermalized neutrons that might otherwise be scattered away from a
single, centrally located detector element. Different geometrical
arrangements may be used while preserving its fundamental
characteristics. Different types of neutron sensing elements may be used,
which may operate on any of a number of physical principles to perform
the function of sensing a neutron, either by a capture or a scattering
reaction, and converting that reaction to a detectable signal. High
detection efficiency, an ability to acquire spectral information, and
directional sensitivity may be obtained.