CALCULATED REFLECTIVITIES OF SUPER-MIRRORS

被引：44

作者：

SCHELTEN, J

MIKA, K

机构：

[1] Institut für Festkörperforschung der Kernforschungsanlage

来源：

NUCLEAR INSTRUMENTS & METHODS | 1979年 / 160卷 / 02期

关键词：

D O I：

10.1016/0029-554X(79)90605-0

中图分类号：

TH7 [仪器、仪表];

学科分类号：

0804 ; 080401 ; 081102 ;

摘要：

Analytical expressions are derived for the layer thicknesses of super-mirrors yielding high neutron reflectivity within a predetermined q interval. The derivation is based on two expressions for the amplitudes of reflected waves as obtained for neutron diffraction from perfect and ideally-imperfect crystals. From these analytical expressions the number and the thicknesses of the double layers, necessary to obtain a required reflectivity within a given q interval for a given pair of substances, can easily be calculated. In addition an exact theoretical treatment of the super-mirror reflectivity is developed which is numerically evaluated to demonstrate the validity of the analytical approximations. By means of computer programs, double layer thicknesses are determined which yield maximum reflectivity for a given number of layers. Optimized layer thicknesses are calculated for super-mirrors consisting of Ni or Cu and Mn or Ti after having incorporated absorption effects into the theoretical treatment. Applications of super-mirrors in neutron scattering are discussed. © 1979.

引用

页码：287 / 294

页数：8