Neutron Reflectivities of Ni-Mn and Ni-Ti Multilayers for Monochromators and Supermirrors
Neutron Reflectivities of Ni-Mn and Ni-Ti Multilayers for Monochromators and Supermirrors
复制标题
用于单色仪和超级镜的 Ni-Mn 和 Ni-Ti 多层膜的中子反射率
DOI：
10.1080/18811248.1979.9730960
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发表时间：
1979
影响因子：
1.2
通讯作者：
S. Okamoto
中科院分区：
文献类型：
--
作者：
T. Ebisawa;N. Achiwa;Shusaku Yamada;T. Akiyoshi;S. Okamoto
在玻璃板上真空交替沉积Ni和Mn或Ni和Ti薄膜，制备了用于中子镜的多层膜。用飞行时间技术测量了它们的中子反射率随中子波长的变化。对于Ni-Mn多层膜单色器，当膜厚为163、112和83埃时，在主布拉格峰处产生接近完美反射（≥90%）所需的膜层数分别为7、11和21。将实验得到的反射率与用常规光学方法计算的反射率进行了比较，两者在定量上是一致的。此外，对于超反射镜，层的数量和层厚度的分布进行了检查，以获得接近统一的反射率下降到比镍的全反射镜的临界波长短得多的波长。由160层Ni和Ti组成的超反射镜的反射率被观察到类似于全反射镜的反射率。
Multilayer films for neutron mirror were made by vacuum depositing thin films of Ni and Mn or Ni and Ti on a glass plate alternately. Their neutron reflectivities were measured as a function of neutron wavelength by the time-of-flight technique. For Ni-Mn multilayer monochromators, the numbers of layers necessary to give a nearly perfect reflection (≥90%) at the main Bragg peak, were found to be 7, 11 and 21 for layer thicknesses of 163, 112 and 83 A, respectively. The reflectivities obtained experimentally were compared with those calculated with the method applying the conventional optics, and their agreements were quantitatively reasonable. Moreover, for supermirrors, the numbers of layers and the distributions of layer thicknesses were examined in order to get a reflectivity of near unity down to the wavelength much shorter than the critical wavelength of a totally reflecting mirror of Ni. The reflectivity of a supermirror consisting of 160 layers of Ni and Ti was observed to behave like that of a tot...