Spin echo modulated small-angle neutron scattering using superconducting magnetic Wollaston prisms

The spin echo modulated small‐angle neutron scattering technique has been implemented using two superconducting magnetic Wollaston prisms at a reactor neutron source. The density autocorrelation function measured for a test sample of colloidal silica in a suspension agrees with that obtained previou...

Full description

Saved in:

Bibliographic Details
Published in:	Journal of applied crystallography Vol. 49; no. 1; pp. 55 - 63
Main Authors:	Li, Fankang, Parnell, Steven R., Bai, Hongyu, Yang, Wencao, Hamilton, William A., Maranville, Brian B., Ashkar, Rana, Baxter, David V., Cremer, J. Ted, Pynn, Roger
Format:	Journal Article
Language:	English
Published:	5 Abbey Square, Chester, Cheshire CH1 2HU, England International Union of Crystallography 01-02-2016
Subjects:	correlation functions Larmor labeling magnetic Wollaston prisms neutron spin echo spin echo modulated small-angle neutron scattering (SEMSANS)
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	The spin echo modulated small‐angle neutron scattering technique has been implemented using two superconducting magnetic Wollaston prisms at a reactor neutron source. The density autocorrelation function measured for a test sample of colloidal silica in a suspension agrees with that obtained previously by other neutron scattering methods on an identically prepared sample. The reported apparatus has a number of advantages over competing technologies: it should allow larger length scales (up to several micrometres) to be probed; it has very small parasitic neutron scattering and attenuation; the magnetic fields within the device are highly uniform; and the neutron spin transport across the device boundaries is very efficient. To understand quantitatively the results of the reported experiment and to guide future instrument development, Monte Carlo simulations are presented, in which the evolution of the neutron polarization through the apparatus is based on magnetic field integrals obtained from finite‐element simulations of the various magnetic components. The Monte Carlo simulations indicate that the polarization losses observed in the experiments are a result of instrumental artifacts that can be easily corrected in future experiments. The spin echo modulated small‐angle neutron scattering technique has been implemented using two superconducting magnetic Wollaston prisms at a reactor neutron source and used to measure the spatial correlation function of colloidal silica particles in a suspension. Monte Carlo simulation is used to understand and further improve the performance.
Bibliography:	ark:/67375/WNG-JX72M4TX-K ArticleID:JCR2VG5028 istex:57E45DC8C57DBDA8A10D6676E4122EBCBB10C316
ISSN:	1600-5767 1600-5767
DOI:	10.1107/S1600576715021573