[Hybrid] Pendellösung Interferometric Determination of the Neutron Charge Radius

by Dr Benjamin J. Heacock (National Institute of Standards and Technology (NIST), USA)

Monday 23 May 2022, 14:30 → 15:30 Europe/Berlin

PH HS 3 (Physics Department)

Neutron Bragg diffraction in the Laue geometry, where the crystal Bragg planes are perpendicular to the neutron entrance and exit faces of a crystal slab, serves as a coherent beam splitter for "perfect" crystal neutron interferometers. A self-interference effect within a single crystal slab, called pendellösung interference, was leveraged to provide precise measures of the neutron-crystalline potentials for the (111), (220), and (400) Bragg reflections in silicon. The large interatomic electric fields experienced by the diffracted neutron provide a 0.1% relative contribution to the measured pendellösung phase shifts, resulting in a determination of the neutron mean square charge radius of -0.1101 ± 0.0089 fm^2. The experimental techniques and results will be described, along with plans for future pendellösung studies.