On the search for neutron EDM using Laue diffraction by a crystal without a centre of symmetry

Abstract

A new method of neutron electric dipole moment (EDM) searching is proposed. It is based on the spin dependence of the Pendellosung phase of a neutron diffracted by a non-centrosymmetric crystal. A two-crystal set-up is proposed and analysed to get the most luminosity possible. A strong interplanar electric field of the crystal and a sufficiently long time for the neutron passage through the crystals for Bragg angles close to n/2 makes it possible to exceed the sensitivity achieved with the ultra cold neutron (UCN) method.

Study of neutron fundamental properties in the perfect crystal optics and diffraction

“…The values of these interplanar fields depend on a momentum direction and energy of neutron in crystal reaching maxima in vicinities of the exact Bragg directions or energies. Such fields give rise for new polarization phenomena [23,[25][26][27][28][29][30][31][32][33] in the neutron Laue diffraction [23,[25][26][27][28][29][30] and in the neutron optics [30][31][32][33] and provide new methods of a search for the neutron electric dipole moment (EDM) [25,27,31,32]. Measurement, for instance, of a spin precession angle for neutron, moving close to the Bragg condition through a thick crystal in such a strong electric field gives hope to improve the limits on the neutron EDM, achieved with the magnetic resonance method using ultracold neutrons (UCN method).…”

Modern Status of Searches for nEDM, Using Neutron Optics and Diffraction in Noncentrosymmetric Crystals

“…The values of these interplanar fields depend on a momentum direction and energy of neutron in crystal reaching maxima in vicinities of the exact Bragg directions or energies. Such fields give rise for new polarization phenomena [13,[15][16][17][18][19][20][21][22][23] in the neutron diffraction [13,[15][16][17][18][19][20] and in the neutron optics [20][21][22][23] and provide new methods of a search for the neutron electric dipole moment (EDM) [15,17,21,22]. Measurement, for instance, of a spin precession angle for neutron, moving close to the Bragg condition through a thick crystal in such a strong electric field gives hope to improve the limits on the neutron EDM, achieved with the magnetic resonance method using ultra cold neutrons (UCN method).…”

Measurement of the neutron electric dipole moment by crystal diffraction

“…The spin rotation can be measured in Bragg [9,10,13] and Laue [14,15,16,17] diffraction geometry. In this paper, we compare both geometries and present preliminary results of a test experiment in Bragg geometry.…”