Transverse coherency of ↑ and ↓ spin neutron waves separated by a pair of composite mirrors using Larmor precession

Larmor precession of neutron spin is represented as a coherent superposition of wave functions of ↑ and ↓ spin ones. Authors measured coherency of ↑ and ↓ spin neutron waves transverse separated by a pair of composite magnetic mirrors with (+,-) and (+,+) arrangements using the Larmor precession. The composite mirror constructed a sequence of permalloy45 thick layer(thickness:800A), germanium gap layer(thickness:D) and nickel thick layer(thickness:800A), and it inserted in front of and behind a π flipper coil at neutron spin interferometer(NSI). The (+,-) and (+,+) arrangements indicate that the first composite mirror is parallel and symmetry to the second one against a neutron beam passing through the π flipper coil, respectively. The transverse separation of ↑ and ↓ spin neutrons reflected by the second mirror in (+,-) and (+,+) arrangements are about 0 and 4D, respectively. Comparing amplitudes of NSE signals in (+,-) and (+,+) arrangements, we can observed transverse coherency of ↑ and ↓ spin neutron waves as a function of distances of ↑ and ↓ spin ones. The transverse coherent length of neutron was estimated to 2μm. (author)