Phase imaging with thermal neutrons

Across four decades, Sam Werner has built and performed elegant neutron interferometry experiments to measure a variety of quantum mechanical phases. These experiments have stringent requirements on experimental conditions and neutron beam conditioning. However, since refractive variations within a sample redistribute neutron intensity transverse to the propagation direction, a simple experimental geometry permits non-interferometric phase measurement and relaxes beam-conditioning requirements. This phase imaging technique, based on the transport of intensity equation, has advantages of allowing weakly absorbing samples to be radiographed at greatly reduced radiation doses, and enabling the use of polychromatic neutrons to increase flux and speed imaging. Furthermore, using other radiations, phase vortices like those of the Aharonov-Bohm effects have been observed. (c) 2006 Elsevier B.V. All rights reserved.