On the resolution of a MIEZE spectrometer

TL;DR

This paper presents an analytical framework for optimizing MIEZE spectrometer resolution, showing that proper geometry can significantly enhance time resolution and extend its applicability in condensed matter physics.

Contribution

It introduces a method to mitigate neutron path length differences in MIEZE spectrometers, enabling higher time resolution through optimized small-angle geometry.

Findings

Resolution can be improved by using small-angle (SANS) geometry.

Time resolution limits are increased by an order of magnitude.

Optimal trade-offs between flux and resolution are analytically determined.

Abstract

We study the effect of a finite sample size, beam divergence and detector thickness on the resolution function of a MIEZE spectrometer. We provide a transparent analytical framework which can be used to determine the optimal trade-off between incoming flux and time resolution for a given experimental configuration. The key result of our approach is that the usual limiting factor of MIEZE spectroscopy, namely neutron path length differences throughout the instrument, can be suppressed up to relatively large momentum transfers by using a proper small-angle (SANS) geometry. Under such configuration, the hitherto accepted limits of MIEZE spectroscopy in terms of time-resolution are pushed upwards by typically an order of magnitude, giving access to most of the topical fields in soft- and hard-condensed matter physics.