Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen

THORPE-WOODS, EDWARD

doi:10.23889/SUThesis.69220

E-Thesis 282 views

Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen / EDWARD THORPE-WOODS

Swansea University Author: EDWARD THORPE-WOODS

E-Thesis under embargo until: 5th February 2026

DOI (Published version): 10.23889/SUThesis.69220

Abstract

Antihydrogen, the simplest pure antimatter atom, can be synthesised and conﬁned for extended periods in the ALPHA experiment at CERN. According to the CPT invariance, antihydro- gen is predicted to exhibit an energy spectrum identical to that of hydrogen. Consequently, a precise comparison of the sp...

Full description

Published:	Swansea University, Wales, UK 2025
Institution:	Swansea University
Degree level:	Doctoral
Degree name:	Ph.D
Supervisor:	Eriksson, S.
URI:	https://cronfa.swan.ac.uk/Record/cronfa69220

first_indexed	2025-04-03T13:21:26Z
last_indexed	2025-04-04T05:16:25Z
id	cronfa69220
recordtype	RisThesis
fullrecord	<?xml version="1.0"?><rfc1807><datestamp>2025-04-03T14:24:53.9004438</datestamp><bib-version>v2</bib-version><id>69220</id><entry>2025-04-03</entry><title>Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen</title><swanseaauthors><author><sid>5cd0756f57de65df317724e6d8365e16</sid><firstname>EDWARD</firstname><surname>THORPE-WOODS</surname><name>EDWARD THORPE-WOODS</name><active>true</active><ethesisStudent>false</ethesisStudent></author></swanseaauthors><date>2025-04-03</date><abstract>Antihydrogen, the simplest pure antimatter atom, can be synthesised and conﬁned for extended periods in the ALPHA experiment at CERN. According to the CPT invariance, antihydro- gen is predicted to exhibit an energy spectrum identical to that of hydrogen. Consequently, a precise comparison of the spectra of both antihydrogen and hydrogen constitutes a di- rect test of CPT invariance. The narrow 1S-2S two-photon transition serves as the gold standard for precision measurements of hydrogen, where it has been measured with an ex- ceptional 15 digits of precision. Equivalent measurements conducted with antihydrogen have so far been limited to 12 digits of precision – this thesis presents work which took place to improve this precision, through updated instrumentation and new methodologies. The stability of the laser frequency was a key limitation in the precision of the previous 1S-2S measurements in antihydrogen. A major focus of this thesis is the development of a new fre- quency metrology suite to improve laser frequency stability, integrating a caesium fountain clock and a hydrogen maser. Preliminary measurements indicate that the upgraded metrology yields a signiﬁcantly more stable laser system which can be used for extremely precise spectroscopy. This thesis also presents preliminary results of the 2023 experimental campaign to improve the precision of the 1S-2S transition in antihydrogen. This eﬀort made use of the signiﬁcantly im- proved laser frequency stability, and is also aided by other new techniques such as laser-cooling of antihydrogen and improved antihydrogen production. Although a full analysis of the experi- mental data is still ongoing, some preliminary approaches presented in this thesis suggest results that may substantially improve the precision of the 1S-2S antihydrogen transition frequency.</abstract><type>E-Thesis</type><journal/><volume/><journalNumber/><paginationStart/><paginationEnd/><publisher/><placeOfPublication>Swansea University, Wales, UK</placeOfPublication><isbnPrint/><isbnElectronic/><issnPrint/><issnElectronic/><keywords>Antimatter, spectroscopy, precision measurements, antihydrogen, frequency metrology, atomic clocks</keywords><publishedDay>5</publishedDay><publishedMonth>2</publishedMonth><publishedYear>2025</publishedYear><publishedDate>2025-02-05</publishedDate><doi>10.23889/SUThesis.69220</doi><url/><notes>A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information.</notes><college>COLLEGE NANME</college><CollegeCode>COLLEGE CODE</CollegeCode><institution>Swansea University</institution><supervisor>Eriksson, S.</supervisor><degreelevel>Doctoral</degreelevel><degreename>Ph.D</degreename><degreesponsorsfunders>EPSRC</degreesponsorsfunders><apcterm/><funders>EPSRC</funders><projectreference/><lastEdited>2025-04-03T14:24:53.9004438</lastEdited><Created>2025-04-03T14:16:41.9497201</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Biosciences, Geography and Physics - Physics</level></path><authors><author><firstname>EDWARD</firstname><surname>THORPE-WOODS</surname><order>1</order></author></authors><documents><document><filename>Under embargo</filename><originalFilename>Under embargo</originalFilename><uploaded>2025-04-03T14:20:35.5294952</uploaded><type>Output</type><contentLength>18288628</contentLength><contentType>application/pdf</contentType><version>E-Thesis</version><cronfaStatus>true</cronfaStatus><embargoDate>2026-02-05T00:00:00.0000000</embargoDate><documentNotes>Copyright: The Author, Edward Thorpe-Woods, 2025</documentNotes><copyrightCorrect>true</copyrightCorrect><language>eng</language></document></documents><OutputDurs/></rfc1807>
spelling	2025-04-03T14:24:53.9004438 v2 69220 2025-04-03 Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen 5cd0756f57de65df317724e6d8365e16 EDWARD THORPE-WOODS EDWARD THORPE-WOODS true false 2025-04-03 Antihydrogen, the simplest pure antimatter atom, can be synthesised and conﬁned for extended periods in the ALPHA experiment at CERN. According to the CPT invariance, antihydro- gen is predicted to exhibit an energy spectrum identical to that of hydrogen. Consequently, a precise comparison of the spectra of both antihydrogen and hydrogen constitutes a di- rect test of CPT invariance. The narrow 1S-2S two-photon transition serves as the gold standard for precision measurements of hydrogen, where it has been measured with an ex- ceptional 15 digits of precision. Equivalent measurements conducted with antihydrogen have so far been limited to 12 digits of precision – this thesis presents work which took place to improve this precision, through updated instrumentation and new methodologies. The stability of the laser frequency was a key limitation in the precision of the previous 1S-2S measurements in antihydrogen. A major focus of this thesis is the development of a new fre- quency metrology suite to improve laser frequency stability, integrating a caesium fountain clock and a hydrogen maser. Preliminary measurements indicate that the upgraded metrology yields a signiﬁcantly more stable laser system which can be used for extremely precise spectroscopy. This thesis also presents preliminary results of the 2023 experimental campaign to improve the precision of the 1S-2S transition in antihydrogen. This eﬀort made use of the signiﬁcantly im- proved laser frequency stability, and is also aided by other new techniques such as laser-cooling of antihydrogen and improved antihydrogen production. Although a full analysis of the experi- mental data is still ongoing, some preliminary approaches presented in this thesis suggest results that may substantially improve the precision of the 1S-2S antihydrogen transition frequency. E-Thesis Swansea University, Wales, UK Antimatter, spectroscopy, precision measurements, antihydrogen, frequency metrology, atomic clocks 5 2 2025 2025-02-05 10.23889/SUThesis.69220 A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. COLLEGE NANME COLLEGE CODE Swansea University Eriksson, S. Doctoral Ph.D EPSRC EPSRC 2025-04-03T14:24:53.9004438 2025-04-03T14:16:41.9497201 Faculty of Science and Engineering School of Biosciences, Geography and Physics - Physics EDWARD THORPE-WOODS 1 Under embargo Under embargo 2025-04-03T14:20:35.5294952 Output 18288628 application/pdf E-Thesis true 2026-02-05T00:00:00.0000000 Copyright: The Author, Edward Thorpe-Woods, 2025 true eng
title	Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen
spellingShingle	Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen EDWARD THORPE-WOODS
title_short	Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen
title_full	Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen
title_fullStr	Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen
title_full_unstemmed	Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen
title_sort	Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen
author_id_str_mv	5cd0756f57de65df317724e6d8365e16
author_id_fullname_str_mv	5cd0756f57de65df317724e6d8365e16_***_EDWARD THORPE-WOODS
author	EDWARD THORPE-WOODS
author2	EDWARD THORPE-WOODS
format	E-Thesis
publishDate	2025
institution	Swansea University
doi_str_mv	10.23889/SUThesis.69220
college_str	Faculty of Science and Engineering
hierarchytype
hierarchy_top_id	facultyofscienceandengineering
hierarchy_top_title	Faculty of Science and Engineering
hierarchy_parent_id	facultyofscienceandengineering
hierarchy_parent_title	Faculty of Science and Engineering
department_str	School of Biosciences, Geography and Physics - Physics{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Biosciences, Geography and Physics - Physics
document_store_str	0
active_str	0
description	Antihydrogen, the simplest pure antimatter atom, can be synthesised and conﬁned for extended periods in the ALPHA experiment at CERN. According to the CPT invariance, antihydro- gen is predicted to exhibit an energy spectrum identical to that of hydrogen. Consequently, a precise comparison of the spectra of both antihydrogen and hydrogen constitutes a di- rect test of CPT invariance. The narrow 1S-2S two-photon transition serves as the gold standard for precision measurements of hydrogen, where it has been measured with an ex- ceptional 15 digits of precision. Equivalent measurements conducted with antihydrogen have so far been limited to 12 digits of precision – this thesis presents work which took place to improve this precision, through updated instrumentation and new methodologies. The stability of the laser frequency was a key limitation in the precision of the previous 1S-2S measurements in antihydrogen. A major focus of this thesis is the development of a new fre- quency metrology suite to improve laser frequency stability, integrating a caesium fountain clock and a hydrogen maser. Preliminary measurements indicate that the upgraded metrology yields a signiﬁcantly more stable laser system which can be used for extremely precise spectroscopy. This thesis also presents preliminary results of the 2023 experimental campaign to improve the precision of the 1S-2S transition in antihydrogen. This eﬀort made use of the signiﬁcantly im- proved laser frequency stability, and is also aided by other new techniques such as laser-cooling of antihydrogen and improved antihydrogen production. Although a full analysis of the experi- mental data is still ongoing, some preliminary approaches presented in this thesis suggest results that may substantially improve the precision of the 1S-2S antihydrogen transition frequency.
published_date	2025-02-05T05:21:46Z
_version_	1851731640326291456
score	11.090464

Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen / EDWARD THORPE-WOODS

Similar Items