E-Thesis 51 views
Towards a Precision Measurement of the 1S-2S Transition in Antihydrogen / EDWARD THORPE-WOODS
Swansea University Author: EDWARD THORPE-WOODS
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...
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Swansea University, Wales, UK
2025
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Eriksson, S. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa69220 |
| 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. |
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| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. |
| Keywords: |
Antimatter, spectroscopy, precision measurements, antihydrogen, frequency metrology, atomic clocks |
| College: |
Faculty of Science and Engineering |
| Funders: |
EPSRC |