eprintid: 10186122
rev_number: 13
eprint_status: archive
userid: 699
dir: disk0/10/18/61/22
datestamp: 2024-03-14 09:20:24
lastmod: 2025-02-01 07:10:22
status_changed: 2024-03-14 09:20:24
type: thesis
metadata_visibility: show
sword_depositor: 699
creators_name: Yao, Han
title: High-sensitivity unshielded radio-frequency atomic magnetometers
ispublished: unpub
divisions: UCL
divisions: B04
divisions: C06
divisions: F60
note: Copyright © The Author 2024. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request.
abstract: This thesis presents an experimental approach to improve the performances of an unshielded single-cell radio-frequency atomic magnetometer (RF-AM) operating in a magnetically noisy environment. Starting with the background and basic principles, the thesis then demonstrates and quantifies improvement in the sensitivity of the magnetometer by sequentially introducing the following modifications in the set-up: in-situ active cancellation of low-frequency magnetic noise,  counter-propagating pumping and multi-pass probing. For this configuration, a detailed optimisation of the experimental parameters was performed, which led to an improvement in sensitivity of  over a factor of three with respect to our previous single-cell single-pump magnetometer. In addition to the upgrades of the hardware setup, optimisation algorithms were introduced.  Specifically,  this thesis describes the optimisation of the collection of data of the unshielded RF-AM based on the uniform design of the experimental parameters space. The proposed procedure is shown to lead to the efficient optimisation of the atomic magnetometer at different frequencies, and it is applicable to both AC and DC sensitivity optimisation. The procedure does not require any detailed prior knowledge of the model underlying the operation of the RF-AM and is effective in reducing the number of experimental runs required for the optimisation. It is ideally suited to the self-calibration of devices without human supervision. For the selection of the optimal operating conditions, general regression neural networks were demonstrated as an effective tool to operate on a small sample of data as input.
date: 2024-01-28
date_type: published
oa_status: green
full_text_type: other
thesis_class: doctoral_embargoed
thesis_award: Ph.D
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 2141641
lyricists_name: Yao, Han
lyricists_id: HYAOX32
actors_name: Yao, Han
actors_id: HYAOX32
actors_role: owner
full_text_status: public
pagerange: 1-168
pages: 168
institution: UCL (University College London)
department: Physics & Astronomy
thesis_type: Doctoral
citation:        Yao, Han;      (2024)    High-sensitivity unshielded radio-frequency atomic magnetometers.                   Doctoral thesis  (Ph.D), UCL (University College London).     Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10186122/2/Thesis_for_University_College_London_HY_revision.pdf