Abstract
An improved data-reduction procedure is proposed and demonstrated for small-angle neutron scattering (SANS) measurements. Its main feature is the correction of geometry- and wavelength-dependent intensity variations on the detector in a separate step from the different pixel sensitivities: the geometric and wavelength effects can be corrected analytically, while pixel sensitivities have to be calibrated to a reference measurement. The geometric effects are treated for position-sensitive 3He proportional counter tubes, where they are anisotropic owing to the cylindrical geometry of the gas tubes. For the calibration of pixel sensitivities, a procedure is developed that is valid for isotropic and anisotropic signals. The proposed procedure can save a significant amount of beamtime which has hitherto been used for calibration measurements.
Highlights
Its main feature is the correction of geometry- and wavelength-dependent intensity variations on the detector in a separate step from the different pixel sensitivities: the geometric and wavelength effects can be corrected analytically, while pixel sensitivities have to be calibrated to a reference measurement
The geometric effects are treated for position-sensitive 3He proportional counter tubes, where they are anisotropic owing to the cylindrical geometry of the gas tubes
The proposed procedure can save a significant amount of beamtime which has hitherto been used for calibration measurements
Summary
Small-angle neutron scattering (SANS) is a commonly used technique to determine the size, shape and arrangement of structures on a mesoscopic length scale in physics, chemistry, biology and materials science (Lindner et al, 2000; Wang et al, 2004; Petoukhov & Svergun, 2005; Davies et al, 2006; SchmidtRohr & Chen, 2008; Fratzl, 2003; Das et al, 2012; Martin et al, 2013; Milde et al, 2013; Gilles et al, 2014; Jaksch et al, 2014; Tokunaga et al, 2015; Lang et al, 2016). Several effects will be discussed that distort the measured intensity: the varying solid-angle coverage of the pixels (a change in the intensity of the order of 50%), shadowing (of the order of 25%), pixel sensitivity (of the order of 10%), scattering angle-dependent sample transmission (of the order of 3%) and the parallax effect (of the order of 1%) Four factors that influence the detected intensity will be discussed in turn: (i) the solid angle covered by the pixels; (ii) an idealized detector efficiency including shadowing and parallax effects; (iii) different pixel sensitivities; and (iv) the sample transmission for scattering at large angles. The combined influence of these factors will be demonstrated on a measured scattering pattern of vanadium
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
