Development and prospect of Very Small Angle Neutron Scattering (VSANS) Techniques

TL;DR

This paper reviews the development, principles, and applications of Very Small Angle Neutron Scattering (VSANS), highlighting technological advances and proposing a new design for the China Spallation Neutron Source.

Contribution

It provides a comprehensive review of VSANS techniques and introduces a new design concept for the CSNS facility.

Findings

Beam current gain factors calculated for various techniques

Detailed analysis of collimation and focusing optics

Proposed VSANS design for CSNS

Abstract

Very Small Angle Neutron Scattering (VSANS) is an upgrade of the traditional Small Angle Neutron Scattering (SANS) technique which can cover three orders of magnitude of length scale from one nanometer to one micrometer. It is a powerful tool for structure calibration in polymer science, biology, material science and condensed matter physics. Since the first VSANS instrument, D11 in Grenoble, was built in 1972, new collimation techniques, focusing optics (multi-beam converging apertures, material or magnetic lenses, and focusing mirrors) and higher resolution detectors combined with the long flight paths and long incident neutron wavelengths have been developed. In this paper, a detailed review is given of the development, principles and application conditions of various VSANS techniques. Then, beam current gain factors are calculated to evaluate those techniques. A VSANS design for the China Spallation Neutron Source (CSNS) is thereby presented.