A source of ultra-cold neutrons for the gravitational spectrometer GRANIT

TL;DR

This paper reports on the development of a high-density ultra-cold neutron source using superfluid helium, aimed at enhancing the capabilities of the GRANIT gravitational spectrometer.

Contribution

It introduces a novel UCN source with improved phase-space density and neutron selection techniques for gravitational experiments.

Findings

UCN can be effectively extracted into vacuum from superfluid helium.

A neutron selection channel maintains high initial density and filters neutrons by vertical velocity.

The source achieves a phase-space density of 0.18 cm^-3(m/s)^-3.

Abstract

We present the status of the development of a dedicated high density ultra-cold neutron (UCN) source dedicated to the gravitational spectrometer GRANIT. The source employs superthermal conversion of cold neutrons to UCN in superfluid helium. Tests have shown that UCN produced inside the liquid can be extracted into vacuum. Furthermore a dedicated neutron selection channel was tested to maintain high initial density and extract only neutrons with a vertical velocity component 20 cm/s for the spectrometer. This new source would have a phase-space density of 0.18 cm-3(m/s)-3 for the spectrometer.