Neutron spectroscopy

Neutron spectroscopy is a <a href="/facts/Spectroscopic/mj71FuNK">spectroscopic</a> method of measuring atomic and magnetic motions by measuring the <a href="/facts/Kinetic_energy/aJRxUd4p">kinetic energy</a> of emitted <a href="/facts/Neutron/oRCM1geb">neutrons</a>. The measured neutrons may be emitted directly (for example, by <a href="/facts/Nuclear_reactions/202yClUr">nuclear reactions</a>), or they may scatter off cold matter before reaching the detector. Inelastic neutron scattering observes the change in the energy and wavevector of the neutron as it scatters from a sample. This can be used to probe a wide variety of different physical phenomena such as the motions of atoms (diffusional or hopping), the <a href="/facts/Rotational_modes/QakXReKL">rotational modes</a> of molecules, sound modes and <a href="/facts/Molecular_vibration/Y0ovRukI">molecular vibrations</a>, recoil in <a href="/facts/Quantum_fluid/bFHpunBN">quantum fluids</a>, magnetic and quantum excitations or even electronic transitions.
Since its discovery, neutron spectroscopy has become useful in medicine as it has been applied to radiation protection and <a href="/facts/Radiation_therapy/j60q5EC6">radiation therapy</a>.
It is also used in <a href="/facts/Fusion_power/jyETSzm4">nuclear fusion</a> experiments, where the neutron spectrum can be used to infer the plasma temperature, density, and composition, in addition to the total fusion power.
Neutron spectroscopy is routinely conducted with a wide range of neutron energies, from as low as a few hundredths of an <a href="/facts/Electronvolt/YMT1fqX9">electronvolt</a> to as high as tens of megaelectronvolts. Much current research focuses on expanding these capabilities to higher energies. In 2001, US researchers were able to measure neutrons with energies up to 100 <a href="/facts/Gigaelectronvolt/YMT1fqX9">gigaelectronvolts</a>

Neutron spectroscopy open-in-new

Neutron spectroscopy