Development of high-precision cold-neutron-interferometry

我们研制了一种新的多层膜冷中子干涉仪，它采用一对气隙为189 mm的分束标准具（BSE）。这是第一个将两条路径完全分开而没有重叠的多层中子干涉仪。在JRR-3装置上，用波长为0.88nm的单色冷中子束，观察到了清晰的干涉条纹，对比度为67%。这一成果将推动长波长中子大尺寸干涉仪的进一步发展，并为慢中子基础物理的新领域开辟道路。

We have developed a new multilayer cold-neutron interferometer using a pair of beam splitting etalons(BSEs) with an air gap of 189 mm in spacing. This is the first multilayer neutron interferometer that separates two paths from each other completely without an overlap. Clear interference fringes with a contrast of 67% have been observed using a monochromatic cold-neutron beam with a wavelength of 0.88 nm at JRR-3.The present accomplishment can advance further development of large-dimensional interferometers for long-wavelength neutrons, and open the way for new field of fundamental physics with slow neutrons.