Demonstration of simultaneous measurement of the spin rotation of dynamically-diffracted neutrons from multiple crystal planes using pulsed neutrons

Abstract

The strong electric field inside a crystal interacting with dynamically-diffracted neutrons by a single crystal can be used in experiments to search for the electric dipole moment of neutrons. This intra-crystal electric field can be evaluated from the neutron spin rotation derived from the dynamical diffraction. Neutron spin rotations from multiple crystal planes were observed simultaneously using pulsed neutrons with a single SiO2 crystal. The spin rotation of dynamically-diffracted neutrons from (110)-crystal plane with the symmetric Laue configuration was consistent with the spin rotation calculated from the intra-crystal electric field reported by the previous experiments. In addition, the spin rotation was also studied for the (02̄1)-, (011)- and (111̄)-crystal planes, which are asymmetric Laue configurations. There have been no previous studies of spin rotations or intra-crystal electric fields on these crystal planes. The experimental results suggest that spin rotation can occur even on crystal planes where it was previously thought that the spin rotation could not occur due to zero intra-crystal electric field. This information is important to study the sensitivity and the systematic uncertainties in nEDM search experiments by crystal diffractions.