Editing Neutron (section)

=== Neutron beams and modification of beams after production ===
Free neutron beams are obtained from [[neutron source]]s by [[neutron transport]]. For access to intense neutron sources, researchers must go to a specialized [[neutron research facility|neutron facility]] that operates a [[research reactor]] or a [[spallation]] source.

The neutron's lack of total electric charge makes it difficult to steer or accelerate them. Charged particles can be accelerated, decelerated, or deflected by [[electric field|electric]] or [[magnetic field]]s. These methods have little effect on neutrons. But some effects may be attained by use of inhomogeneous magnetic fields because of the [[neutron magnetic moment|neutron's magnetic moment]]. Neutrons can be controlled by methods that include [[neutron moderator|moderation]], [[neutron reflector|reflection]], and [[neutron-velocity selector|velocity selection]]. [[Thermal neutron]]s can be polarized by transmission through [[magnet]]ic materials in a method analogous to the [[Faraday effect]] for [[photon]]s. Cold neutrons of wavelengths of 6–7 angstroms can be produced in beams of a high degree of polarization, by use of [[neutron supermirror|magnetic mirrors]] and magnetized interference filters.<ref>Byrne, J. ''Neutrons, Nuclei, and Matter'', Dover Publications, Mineola, New York, 2011, {{ISBN|0486482383}}, p. 453.</ref>