中文摘要：

中子超镜的主要光学性能指标是反射临界角,反射临界角通常由镍块体材料的全反射临界角的倍数m来表征。本文采用增加帽层、优化关键参数和引入新设计参数的方法,弥补了中子超镜算法在m≤1区域内的局限性,实现了包含较少膜对数K的大m值中子超镜结构设计。利用Nevot-Croce模型模拟了多层膜的非理想界面,讨论了多层膜表界面粗糙度对超镜反射特性的影响。结果表明,对m=3的Ni/Ti中子超镜仅需200个膜对,在制作工艺上,要求制备m=3的Ni/Ti超镜的膜层界面粗糙度应小于1.5 nm,以保证其反射率不低于80%。

英文摘要：

An important property of a supermirror is its critical angle,which is measured in multiples m of the critical angle of bulk nickel by convention.Adding Ni capping layer on the outmost of supermirrors,optimizing its key parameter ξ0 and introducing a novel parameter to design neutron supermirrors can offset the reflectivity limitation in m≤1 region.The designed Ni/Ti neutron supermirror has less bi-layer pairs（K=200） and large m value（m=3）,which would be easier to fabricate.The effects of the surface and interfacial roughness on neutron supermirrors were discussed by using Nevot-Croce model to simulate the non-ideal interface of the supermirror.The calculation result shows that 1.5 nm interfacial roughness should be required to make m=3 neutron supermirror with 200 bi-layer pairs and more than 80% critical reflectivity.