Focusing neutron reflectometry: Implementation and experience on the TOF-reflectometer Amor
Focusing neutron reflectometry: Implementation and experience on the TOF-reflectometer Amor
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聚焦中子反射计：TOF 反射计 Amor 的实施和经验
DOI：
10.1016/j.nima.2016.03.007
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发表时间：
2016
影响因子：
1.4
通讯作者：
A. Glavic
中科院分区：
文献类型：
--
作者：
J. Stahn;A. Glavic
中子反射计是研究表面附近化学和磁性深度剖面的强大工具。中子与X射线相比的优点是对同位素敏感、穿透能力高以及对磁感应强度高。然而，最大的缺点是可用通量低，这导致对更大的样品进行更长的计数时间。为了提高中子反射计的性能，近年来开发并实现了聚焦引导系统。在这里，我们报告了这种 Selene 波导的小型演示器的应用和性能，该演示器作为附加组件安装在 PSI 的飞行时间 (TOF) 反射计 Amor 上。由于导轨尺寸有限，磁通量集中在最多 2 毫米宽度的占地面积上。因此，即使在小样品上也可以避免接触点的照明。尽管在 Amor 上测量的尺寸为 10× 10 mm 2 的典型样品明显处于照明不足的情况，但所提出的设置使计数时间减少了 80%。因此，使用演示器可以在 q z 范围从 0.005 Å− 1 到 0.08 Å− 1 的范围内进行几分钟的时间分辨率的现场或现场研究。除了简要概述聚焦反射计的概念外，还给出了数据缩减及其质量的详细描述，然后是一个应用示例。
Neutron reflectometry is a powerful tool to investigate chemical and magnetic depth profiles near surfaces. The advantages of neutrons compared to x-rays are their sensitivity to isotopes, the high penetration capabilities and the high sensitivity to magnetic induction. The biggest disadvantage however is the low flux available, which leads to much longer counting times on much larger samples. In order to boost the performance of neutron reflectometers, a focusing guide system was developed and realised over recent years. Here we report on the application and performance of a down-scaled demonstrator of such a Selene guide, installed as an add-on on the time-of-flight (TOF) reflectometer Amor at the PSI. Due to the limited size of the guide, the flux is concentrated to a footprint of at most 2 mm width. It is thus possible to avoid illumination of contacts even on small samples. Despite the fact that typical samples measured on Amor with a size of 10× 10 mm 2 are markedly under illuminated, the presented set-up leads to a reduction in counting time of 80%. The use of the demonstrator thus allows for in-situ or in-operando investigations with a time resolution of a few minutes for a q z range from 0.005 Å− 1 to 0.08 Å− 1. Besides a short recapitulation of the concept of focusing reflectometry, a detailed description of the data reduction and its quality is given, followed by an application example.