Redoubled effect of a neutron spin rotation in deformed noncentrosymmetric crystal for the Bragg diffraction scheme

Abstract

A doubled effect of a neutron spin rotation in a noncentrosymmetric quartz crystal for the Bragg reflected neutrons from the deformed exit crystal side is first observed. The effect arises due to a neutron Schwinger interaction with the crystal and depends on the value of the crystal deformation near its back exit face. The electric field acting on a neutron in the quartz crystal is about ∼108 V/cm. This field affects the neutron during the whole time of its passage through the crystal, both there and back. This time is limited only by the available size of the crystal (14 and 27 cm in our case) or the neutron absorption length. Observation of such effects gives a real perspective on the essential improvement of the scheme and sensitivity of the experiment in the search for a neutron electric dipole moment (EDM) by the crystal-diffraction technique. Moreover, the presented experimental scheme can be applied for a neutron with an energy close to the P wave resonance to search for the T-odd part of a neutron-nuclei interaction, for example, because of relatively low requirements of crystal quality.