Stroboscopic time-of-flight neutron diffraction during cyclic testing using the event data recording system at J-PARC1

摘要

A time-resolved time-of-flight neutron diffraction technique to characterize the structural properties of materials during cyclic tests has been developed for the neutron diffractometers at J-PARC. Using this technique, diffracted neutrons and the applied cyclic conditions are recorded as event data together with time information. The amplitude and phase of the conditions of all recorded neutron signals can be specified by using the characteristics of the event data. By adopting the developed technique, the behaviors of the crystal lattice and domains of the piezoelectric material in a multilayer-type piezoelectric actuator driven by a cyclic electric field were evaluated. The developed technique enabled the collection and processing of diffraction data for all levels of the applied electric field, as opposed to only the highest and lowest levels. The variation in diffraction intensity during the application of a cyclic electric field was obtained successfully, and the hysteresis-like behaviors of both the lattice strain and the 90° domain switching were revealed.