Description
- Abstract:
- Light pulse atom interferometry (LPAI) is a technique capable of producing incredibly accurate measurements of an atom and can be applied to many novel forms of quantum sensing. LPAI can be used to measure gravity and has demonstrated a precision on the order of 10^-9 in other lab-based experiments, which can exceed the state of the art of classical gravimeters. Such laboratory setups are large and not constructed in a form capable of being deployed in the field. Moreover, they operate at slow repetition rates and are highly susceptible to vibration and inertial variations. This thesis presents the construction and operation of an LPAI gravimeter built in a form factor capable of being deployed on a surface ship at sea. Two at-sea excursions are demonstrated, with the gravimeter producing measurements that successfully aid in an inertial navigation solution. The coupling of the LPAI gravimeter with a high-bandwidth MEMS accelerometer forms a hybrid sensor through a "feedforward-feedback" scheme that enables the measurement of specific force while subject to a large range of dynamic motion. A sub-µg-scale sensitivity is achieved, with an absolute accuracy of 10 µg and a stability floor of 150 ng over multiple weeks. Additional land-based field testing is performed to demonstrate viability of the LPAI gravimeter outside of a laboratory environment. Further improvements of sensor performance are investigated, especially absolute accuracy and long-term stability, with the goal of producing a gravimeter capable of making reliable measurements of gravity at sub-µg accuracy over many years. Spurious phase shifts in the interferometer sequence that produce gravimeter accuracy errors are studied, and efforts to mitigate or suppress them are presented.
- Notes:
- Thesis (Ph. D.)--Brown University, 2025
Citation
Baumgart, Aaron Paul,
"A Light Pulse Atom Interferometric Gravimeter in Dynamic Environments"
(2025).
Physics Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://repository.library.brown.edu/studio/item/bdr:mfyhnw9u/
