A portable cold atom gravity gradiometer with field application performance

Download Statistics

Downloads

Downloads per month over past year

Stray, Ben ORCID: https://orcid.org/0000-0003-1264-552X (2021). A portable cold atom gravity gradiometer with field application performance. University of Birmingham. Ph.D.

Preview

Stray2021PhD.pdf
Text - Accepted Version
Available under License All rights reserved.
Download (3MB) | Preview

Abstract

A cold atom interferometer is operated in a gradiometer configuration, to overcome the challenges presented by gravity sensing in a civil engineering environment. Such operation allows for the suppression of common mode noise sources, including vibration and environmental effects. Through integration of the instrument into a sensor and control package, the sensor package may be readily carried by two persons in order to operate in the field. An all-in-fibre laser system is used to reduce effects of mechanical shocks associated with transportation and operation outside. The cold atom system is shown to work repeatably over a broad ambient temperature range, with atom numbers of 105 participating in each interferometer, at temperatures of (2.86 ± 0.09) µK and (3.7 ± 0.2) µK for the top and bottom clouds, respectively. The gravity gradiometer demonstrates the same performance in and out of the laboratory, with an outdoor performance of (466 ± 8) E/√Hz, at a 0.67 Hz measurement bandwidth, integrating to a resolution of 17 E. A sensitivity to tilt three times less than an ideal gravimeter is measured, allowing for operation in more challenging environments. Measurements of changes in gravity gradient are demonstrated through the modulation of test masses, resolving signal changes below 50 E. The sensor is operated in a civil engineering environment, demonstrating point to point repeatability of (52 ± 40) E.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):