Investigation on possibility of neutron electric optical devices based on piezoelectric single crystals

A principle verification experiment of neutron electric optical devices using piezoelectric single crystals was carried out. This neutron electric optical device can change its d-spacing by applying an electric field to the crystal, which results in change of the Bragg diffraction angle. Although an α-quartz has a small piezoelectric strain constant, an α-quartz was used in this experiment because characteristics of α-quartz are well known and it is easy to obtain high quality and large size single crystals. At first, macroscopic distortion and change of thickness caused by an applied electric field were observed by using laser interferometers. Thus, double crystal diffraction measurement using 4.7 Å cold neutrons was carried out. For these experiments, DC bias voltage was applied to the crystal. As a result, peaks of rocking curves were shifted 14 s at 500 V and 2 min at 1000 V from their original positions. These values were approximately one figure larger than the theoretical values; therefore, these results were influenced by macroscopic bending of the crystal. From these results, it can be concluded that the possibility of neutron electric optical devices using not only change of d-spacing but also macroscopic bending of piezoelectric crystal was confirmed.