1. n. [Formation Evaluation]

A neutron interaction in which the kinetic energy lost by a neutron in a nuclear collision is transferred to the nucleus. The energy of a neutron is reduced more efficiently in collisions with nuclei of similar mass to the neutron, like hydrogen and other elements of low atomic mass. Elastic neutron scattering is one of the main principles behind the neutron porosity log, as well as the pulsed neutron capture log, which is mainly used to determine water saturation behind casing.

See: chemical neutron source,  inelastic neutron scattering,  neutron capture,  neutron generator,  neutron interactions,  neutron porosity,  water saturation