Demonstration of Novel Neutron Interferometer for Fundamental Physics

Neutron interferometers can measure interactions acquired by neutron waves with high sensitivity. In previous research, it has been widely used for fundamental physics experiments such as the measurement of neutron-nuclear scattering length, verification of earth gravity, verification of spinor 4π rotation symmetry, and the search for exotic interactions. However, its measurement sensitivity has not evolved significantly over the past 50 years, and the development of high-sensitivity interferometers is necessary for the precise measurement of physical quantities.

​​​The measurement sensitivity of the interferometer is proportional to the neutron wavelength and the interaction length. We have developed a novel neutron interferometer using multilayer neutron mirrors, which can use longer wavelengths and longer interaction lengths compared to the conventional interferometer. The use of pulsed neutron beams and time-of-flight methods can significantly increase the number of neutrons used and suppress systematic uncertainties based on the wavelength-dependent information of the interference fringes. Thanks to the fully two-path separation, the measurement of neutron-nuclear scattering lengths obtained by insertion of solid samples has been realized. The measured neutron-nuclear scattering lengths for several nuclei were consistent with the literature values. In this talk, we report the result of the demonstration of the novel neutron interferometer.