Drs. Bernstein and Horne propose to investigate neutron interferometry and diffraction. These investigations include development of new sensitive probes of matter and study of fundamental quantum phenomena. This project continues the ten year collaboration with Professor Shull at MIT, a collaboration that has played a central role in the development of neutron interferometry. As a probe, neutrons in crystals are more sensitive to perturbing influences than in free space. Both the effective mass enhancement and that of a new resonance phenomenon will be exploited. This new resonance occurs when in-crystal neutrons are subject to a homogeneous magnetic field of the proper magnitude. They will study possible improvements in the effective mass enhancements, possible combinations of the two effects, their application to search for other neutron properties, e.g., the electric dipole moment, and the possibility of using ferroelectric crystal diffraction for even greater sensitivity. On the theoretical side, they also expect to investigate refinements in the application of the gravitational equivalence principle, the description of the Fizeau effect (phase shift in a moving medium) and an exact analogy to the one- dimensional Dirac equation. Experimental tests will be performed at a facility being installed at Grenoble and, if possible, at the planned NBS cold neutron source. This work on interferometry leads to fundamental quantum principles and effects. Here they intend to pursue a newly discovered system that violates Bell's inequality but, like the original EPR experiment, does not involve spin. They will also continue their coherence studies including the nature of neutron wave-packets and investigations of exact spin rotation symmetry.
