Displacement-noise-free interferometeric gravitational-wave detector using unidirectional neutrons with four speeds

For further gravitational wave (GW) detections, it is significant to invent a technique to reduce all kinds of mirror displacement noise dominant at low frequencies for ground-based detectors. The neutron displacement-noise-free interferometer (DFI) is one of the tools to reduce all the mirror displacement noise at lower frequencies. In this paper, we describe a further simplified configuration of a neutron DFI in terms of neutron incidence direction. In the new configuration, neutrons enter the interferometer with unidirectional incidence at four speeds as opposed to two bidirectional incidences of opposite directions at two speeds as reported previously. This simplification of the neutron DFI is significant for proof-of -principle experiments.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

To detect gravitational waves more effectively, it is important to develop a technique for reducing mirror displacement noise in ground-based detectors at low frequencies. The neutron displacement-noise-free interferometer (DFI) is a tool that can minimize mirror displacement noise in the lower frequency range. This paper presents a simplified configuration of the neutron DFI based on the direction of neutron incidence. Unlike the previous configuration, which involved bidirectional incidences at two speeds, the new configuration allows unidirectional neutron incidence at four speeds. This simplification is crucial for proof-of-principle experiments.