Development of the very low energy neutron beam transportation and bending system

几种中子反射镜已经被开发出来，用于传输和弯曲极低能量的中子。1)研制了用于高辐照场的抛光玻碳中子反射镜。2)研制了在两片硅片上叠加多层的宽带单色仪。中子反射波长由单层的26 ~ 40 nm扩大到19 ~ 40 nm。3)研制了氘化类金刚石碳中子反射镜。它也有可能制造出一种自由形状的反射镜，用于形状复杂的中子导管、中子弯管和聚焦装置。4)尝试了超低温中子射线照相技术作为超低能中子的新应用。水厚度分辨率小于0.1 mm。VCN射线照相可以显示在干燥过程中花中水量的变化。

Several kind of neutron mirrors have been developed to transport and bend very low energy neutrons. 1) Polished glassy carbon neutron mirrors for high irradiation field was developed. 2) Wide band monochromator consisting of a stack of multilayers on two Si wafers was developed. The neutron reflection wavelength was broadened to 19 - 40 nm by this stack from 26 - 40 nm of one multilayer. 3) Deuterated diamond-ike carbon as neutron mirrors was developed. It also has a possibility of making a free shape mirror to be useful for neutron guide tube with complicated shape, neutron bender and focusing devices. 4) Very cold neutron radiography as the new aplication of very low energy neutrons was tried. The resolution of water thickness is less than 0.1 mm. VCN radiography can show the change of water quantity in flowers during a drying procedure.