Time-of-flight Fourier UCN spectrometer

TL;DR

This paper introduces a novel time-of-flight Fourier spectrometer designed for ultra-cold neutron (UCN) diffraction studies, capable of measuring UCN energy spectra with high resolution in the 60-200 neV range.

Contribution

The paper presents a new spectrometer operating at discrete modulation frequencies, enabling precise UCN energy spectrum measurements with high resolution.

Findings

Spectrometer successfully measured UCN energy spectra in the 60-200 neV range.

Achieved energy resolution of approximately 5 neV.

Estimated accuracy of line position determination is on the order of 10^{-10} eV.

Abstract

We describe a new time-of-flight Fourier spectrometer for investigation of UCN diffraction by a moving grating. The device operates in the regime of a discrete set of modulation frequencies. The results of the first experiments show that the spectrometer may be used for obtaining UCN energy spectra in the energy range of 60$\div$200 neV with a resolution of about 5 neV. The accuracy of determination of the line position was estimated to be several units of $10^{-10}$ eV