In physics, quasielastic scattering designates a limiting case of inelastic scattering

Inelastic scattering

In particle physics and chemistry, inelastic scattering is a fundamental scattering process in which the kinetic energy of an incident particle is not conserved . In an inelastic scattering process, some of the energy of the incident particle is lost or gained...

, characterized by energy transfers being small compared to the incident energy of the scattered particles.

The term was originally coined in nuclear physics.

It was applied to thermal neutron scattering

Neutron scattering

Neutron scattering,the scattering of free neutrons by matter,is a physical processand an experimental technique using this processfor the investigation of materials.Neutron scattering as a physical process is of primordial importance...

 by Leon van Hove

Léon Van Hove

Léon Van Hove was a Belgian physicist and a former Director General of CERN. He developed a scientific career spanning mathematics, solid state physics, elementary particle and nuclear physics to cosmology.-Biography:...

 and Pierre Gilles de Gennes
(quasielastic neutron scattering

Quasielastic neutron scattering

Quasielastic neutron scattering designates a limiting case of inelastic neutron scattering, characterized by energy transfers being small compared to the incident energy of the scattered particles....

, QENS).

Finally, it is sometimes used for Dynamic light scattering

Dynamic light scattering

thumb|right|350px|Hypothetical Dynamic light scattering of two samples: Larger particles on the top and smaller particle on the bottomDynamic light scattering is a technique in physics that can be used to determine the size distribution profile of small particles in suspension or polymers...

(also known by the more expressive term photon correlation spectroscopy).