The neutron interferometer, developed by Werner and Rauch in the 1970's, splits the neutron matter wave into two paths by Bragg diffraction in a perfect silicon crystal, then recombines them coherently to produce an interference signal measured by a neutron counter, thereby directly obtaining an interaction amplitude via the phase shift. It has been used to make famous demonstrations of quantum phenomena such as the gravitationally induced phase shift and the 4π rotation symmetry of a spinor. It is also an ideal instrument for precision measurement of low-energy neutron scattering lengths that are important for developing and testing nuclear potential models and effective field theories, probing neutron substructure, and in searching for new short-range forces. I will describe previous experiments and the current program at the NIST Neutron Interferometry and Optics Facility. This work is supported by NSF and NIST (U.S. Dept. of Commerce).
Argonne Physics Division Colloquium Schedule