Measurement of longitudinal coherence length of neutron by time resolving method using high-frequency cold neutron pulser

The measurement methods of a longitudinal coherence length of neutron without the effect of wave length diffraction and divergence were discussed. To determine it, we developed an element which can generate 1 KHz polarized cold neutron pulse by setting permalloy (Fe(55%) Ni(45%)/Ge multilayer film magnetic mirror) in ±15 gauss pulse magnetic field. The experimental conditions were set up in order to determine the longitudinal coherence length. An arrangement of cold neutron phase-spin echo interferometer using a pair of identical multilayer spin splitters (MSS) and the experimental arrangement for the measurement of the coherence length of the neutron using a high-frequency cold neutron pulser, time-space diagram for the neutron with passing through the system for measurement of the longitudinal coherence length of the neutron using time resolving method and structure of the magnetic circuit for producing a high-frequency magnetic field were shown. (S.Y.)