Ewald construction and resolution function for rocking-curve small-angle neutron scattering experiments

2007 ◽  
Vol 40 (5) ◽  
pp. 959-963 ◽  
Author(s):  
Nikolaos Daniilidis ◽  
Ivo Dimitrov ◽  
Xinsheng Sean Ling
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Flux Line ◽  
Preferential Orientation ◽  
Type Ii ◽  
Resolution Function ◽  
Rocking Curve ◽  
Type Ii Superconductors ◽  
Numerical Integrations

A geometrical Ewald construction for small-angle neutron scattering experiments from line-like objects with a preferential orientation of the lines, such as flux-line lattices in type-II superconductors, is described. The Ewald construction offers a straightforward way to interpret rocking-curve experiments. It allows calculation of the resolution function in rocking-curve measurements. The resolution function for a given instrumental geometry can be readily computed by performing two numerical integrations.

Toward a new lower limit for the minimum scattering vector on the very small angle neutron scattering spectrometer at Laboratoire Léon Brillouin

2008 ◽  
Vol 41 (1) ◽  
pp. 161-166 ◽  
Author(s):  
Annie Brûlet ◽  
Vincent Thévenot ◽  
Didier Lairez ◽  
Sébastien Lecommandoux ◽  
Willy Agut ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Pixel Size ◽  
Resolution Function ◽  
Incident Wavelength ◽  
Under Construction ◽  
Very High ◽  
Good Agreement ◽  
Small Pixel

The main characteristics of the very small angle neutron scattering spectrometer (VSANS) under construction at the Laboratoire Léon Brillouin are a multibeam pinhole collimator converging onto an image plate detector. By combining tiny collimation (diaphragms of around 1 or 2 mm in diameter) with the small pixel size of the detector (0.15 × 0.15 mm), very high resolution measurements can be achieved. The resolution function of the instrument contains a contribution from gravity, which is reduced by the intermediate masks of the collimator. Owing to the relatively short length of the VSANS instrument (around 14 m), this effect remains weak, in good agreement with the predictions. With a prototype multibeam collimator, an incident wavelength of 0.9 nm and the detector located at 6 m from the sample, it is possible to accessqvalues as low as 4 × 10−3 nm−1with very highqresolution. Promising preliminary experiments with highqresolution are reported, which open up new fields to the SANS technique.

scholarly journals Structural Stability of the Square Flux Line Lattice inYNI2B2CandLuNi2B2CStudied with Small Angle Neutron Scattering

1997 ◽  
Vol 79 (3) ◽  
pp. 487-490 ◽  
Author(s):  
M. R. Eskildsen ◽  
P. L. Gammel ◽  
B. P. Barber ◽  
A. P. Ramirez ◽  
D. J. Bishop ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Structural Stability ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Flux Line ◽  
Line Lattice ◽  
Flux Line Lattice

Effects of Shear on the Structures in a System of Small Rodlike Micelles

1994 ◽  
Vol 376 ◽  
Author(s):  
Paul D. Butler ◽  
L.J. Magid ◽  
William A. Hamilton ◽  
P.J. Kreke ◽  
Johnb. Hayter
Keyword(s):  
Shear Rate ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Supporting Electrolyte ◽  
Type Ii ◽  
Spherical Micelles ◽  
Shear Induced Structure ◽  
Induced Structure

ABSTRACTWe have used small angle neutron scattering (SANS) to study solutions of cetyltrimethylammonium 2,6-dichlorobenzoate (2,6) at rest and as a function of shear. These solutions are Newtonian, and up to a concentration of at least 100mM contain spherical micelles. Comparison with viscoelastic solutions of the closely related, and much studied, cetyltrimethylammonium 3,5-dichlorobenzoate (3,5) is made. While spheres are not expected to align under shear, a shear induced sphere to rod transition has been postulated for this system. In the results presented here, no shear induced sphere to rod transition was observed even at the highest accessible shear rate. Addition of sufficient supporting electrolyte (up to 1M NaCl) does cause such a transition in the quiescent solution. Hoffmann et al. have seen what they refer to as the formation of a shear induced structure (SIS or type II micelles) on similar systems where short rods form in the absence of supporting electrolyte. Shearing of the salted system produces rapid though not spectacular alignment, with no evidence of a SIS forming.

Sign in / Sign up

Export Citation Format

Share Document