scholarly journals Dynamical theory: Application to spin-echo resolved grazing incidence scattering from periodic structures

2011 ◽  
Vol 110 (10) ◽  
pp. 102201 ◽  
Author(s):  
Rana Ashkar ◽  
W. L. Schaich ◽  
V. O. de Haan ◽  
A. A. van Well ◽  
R. Dalgliesh ◽  
...  
Keyword(s):  
Periodic Structures ◽  
Spin Echo ◽  
Grazing Incidence ◽  
Dynamical Theory ◽  
Theory Application

Comparison of dynamical theory and phase-object approximation for neutron scattering from periodic structures

2011 ◽  
Vol 44 (5) ◽  
pp. 958-965 ◽  
Author(s):  
Rana Ashkar ◽  
V. O. de Haan ◽  
A. A. van Well ◽  
R. Dalgliesh ◽  
J. Plomp ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Periodic Structures ◽  
Good Description ◽  
Spin Echo ◽  
Diffraction Gratings ◽  
Grazing Incidence ◽  
Dynamical Theory ◽  
Neutron Spin ◽  
Phase Object ◽  
Neutron Spin Echo

Dynamical theory (DT) calculations have been successfully developed to explain neutron spin-echo resolved grazing-incidence scattering from diffraction gratings. The theory, without any adjustable parameters, has been shown in previous publications to accurately reproduce the sensitivity of the spin-echo polarization signal to sample specifications and scattering geometry. The phase-object approximation (POA), which is computationally less demanding than the DT, has also been used to analyze neutron spin-echo polarization data obtained from diffraction gratings. In this paper, POA and DT calculations are compared for neutron scattering from various diffraction gratings in different geometrical settings. POA gives a good description of the data for transmission cases, where the neutron beam is incident at large angles to the average grating surface. However, for the grazing-incidence reflection cases that were studied, the POA does not fit the data using the independently determined dimensions of the measured gratings. On the other hand, the good agreement between dynamical theory and the data from gratings with known profiles paves the way for its use to extract profile information from periodic samples with unknown structures.

scholarly journals Dynamical theory calculations of spin-echo resolved grazing-incidence scattering from a diffraction grating

2010 ◽  
Vol 43 (3) ◽  
pp. 455-465 ◽  
Author(s):  
Rana Ashkar ◽  
P. Stonaha ◽  
A. L. Washington ◽  
V. R. Shah ◽  
M. R. Fitzsimmons ◽  
...  
Keyword(s):  
Diffraction Grating ◽  
Continuous Wave ◽  
Spin Echo ◽  
Grazing Incidence ◽  
Grating Period ◽  
Dynamical Theory ◽  
Neutron Spin ◽  
Wave Source ◽  
Rectangular Profile ◽  
Good Account

Neutrons scattered or reflected from a diffraction grating are subject to a periodic potential analogous to the potential experienced by electrons within a crystal. Hence, the wavefunction of the neutrons can be expanded in terms of Bloch waves and a dynamical theory can be applied to interpret the scattering phenomenon. In this paper, a dynamical theory is used to calculate the results of neutron spin-echo resolved grazing-incidence scattering (SERGIS) from a silicon diffraction grating with a rectangular profile. The calculations are compared with SERGIS measurements made on the same grating at two neutron sources: a pulsed source and a continuous wave source. In both cases, the spin-echo polarization, studied as a function of the spin-echo length, peaks at integer multiples of the grating period but there are some differences between the two sets of data. The dynamical theory explains the differences and gives a good account of both sets of results.

Comment on “Grazing incidence X-ray fluorescence of periodic structures – a comparison between X-ray standing waves and geometrical optics calculations” by F. Reinhardt, S. H. Nowak, B. Beckhoff, J-C. Dousse and M. Schoengen, JAAS, 2014, 29, 1778

2015 ◽  
Vol 30 (12) ◽  
pp. 2548-2550
Author(s):  
W. Jark ◽  
D. Eichert
Keyword(s):  
Physical Model ◽  
Periodic Structures ◽  
Standing Waves ◽  
Grazing Incidence ◽  
Data Interpretation ◽  
Geometrical Optics ◽  
X Ray ◽  
Model Based ◽  
Published Paper

The data interpretation in the recently published paper with the above title is criticized and it is shown that an alternative more physical model based on diffraction in periodic structures can explain the data better and more consistently.

scholarly journals Grazing Incidence Neutron Spin Echo Study of Poly(N-isopropylacrylamide) Brushes

2020 ◽  
Vol 53 (5) ◽  
pp. 1819-1830 ◽  
Author(s):  
Judith Witte ◽  
Patrick Krause ◽  
Tetyana Kyrey ◽  
Anna Margarethe Dahl ◽  
Jana Lutzki ◽  
...  
Keyword(s):  
Spin Echo ◽  
Grazing Incidence ◽  
Neutron Spin ◽  
Neutron Spin Echo

A spin-echo resolved grazing incidence scattering setup for the neutron interrogation of buried nanostructures

2009 ◽  
Vol 80 (12) ◽  
pp. 123903 ◽  
Author(s):  
János Major ◽  
Alexei Vorobiev ◽  
Adrian Rühm ◽  
Ralf Maier ◽  
Márton Major ◽  
...  
Keyword(s):  
Spin Echo ◽  
Grazing Incidence ◽  
Neutron Interrogation

Diffuse Neutron Scattering from Surfaces and Interfaces

1994 ◽  
Vol 376 ◽  
Author(s):  
Sunil K. Sinha
Keyword(s):  
Neutron Scattering ◽  
Diffuse Scattering ◽  
Specular Reflection ◽  
Grazing Incidence ◽  
Magnetic Multilayers ◽  
Dynamical Theory ◽  
X Ray ◽  
Specular Scattering ◽  
Surfaces And Interfaces ◽  
Diffuse Neutron

ABSTRACTThe use of neutron scattering as a tool for exploring surfaces and interfaces has become more prevalent over the last several years, mainly due to the increasing popularity of reflectivity techniques, which study specular reflection from single surfaces or multilayers. Due to intensity limitations, the use of off-specular or grazing-incidence neutron scattering techniques has been much less prevalent. In this paper we shall discuss the origins of magnetic off-specular scattering (e.g., as observed in magnetic multilayers) and the origins of anomalies seen in the X-ray or neutron diffuse scattering from multilayers near Bragg reflections in terms of the Dynamical Theory of Scattering.

scholarly journals Using Neutron Spin Echo Resolved Grazing Incidence Scattering to Investigate Organic Solar Cell Materials

10.3791/51129 ◽  
2014 ◽  
Author(s):  
Andrew J. Parnell ◽  
Adam Hobson ◽  
Robert M. Dalgliesh ◽  
Richard A. L. Jones ◽  
Alan D. F. Dunbar
Keyword(s):  
Solar Cell ◽  
Organic Solar Cell ◽  
Spin Echo ◽  
Grazing Incidence ◽  
Neutron Spin ◽  
Neutron Spin Echo
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