The Very Small-Angle Neutron Scattering Instrument at the National Institute of Standards and Technology

Published

April 1, 2022

Author(s)

John Barker, James Moyer, Steven Kline, G. Jensen, Jeremy Cook, Cedric Gagnon, Elizabeth Kelley, Jean Philippe Chabot, Nicholas C. Maliszewskyj, Chirag Parikh, Wangchun Chen, Ryan Murphy, C. Glinka

Abstract

A description and the performance of the Very Small-Angle Neutron Scattering (VSANS) Diffractometer at the National Institute of Standards and Technology are presented. The measurement range of the instrument extends over three decades of momentum transfer q from 2x10^-4 Å^-1 to 0.7 Å^-1. The entire scattering angle range from 8x10^-5 rad to π/6 rad (30˚) can be measured simultaneously using three separate detector carriages on rails holding nine two-dimensional detector arrays. Versatile choices of collimation options and neutron wavelength selection allow the q-resolution and beam intensity to be optimized for the needs of the experiment. High q-resolution is achieved using multiple converging beam collimation with circular pinholes combined with refractive lenses and prisms. Relaxed vertical resolution with much higher beam intensity can be achieved with narrow slit collimation and broad wavelength range chosen by truncating the moderator source distribution below 4 Å with a Be crystalline filter and above 8 Å with a supermirror deflector. Polarized beam measurements with full polarization analysis are also provided by a high-performance supermirror polarizer and spin flipper, capable of producing flipping ratios of over 100, along with a high efficiency ³He polarization analyzer.

Citation

Journal of Applied Crystallography

Volume

55

Issue

2

Pub Type

Journals

Download Paper

https://doi.org/10.1107/S1600576722000826

Local Download

Keywords

Small-angle scattering, Neutron, Instrumentation

Citation

Barker, J. , Moyer, J. , Kline, S. , Jensen, G. , Cook, J. , Gagnon, C. , Kelley, E. , Chabot, J. , Maliszewskyj, N. , Parikh, C. , Chen, W. , Murphy, R. and Glinka, C. (2022), The Very Small-Angle Neutron Scattering Instrument at the National Institute of Standards and Technology, Journal of Applied Crystallography, [online], https://doi.org/10.1107/S1600576722000826, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933266 (Accessed October 14, 2025)