E-Thesis 169 views 19 downloads
Systematic studies of positron accumulation and transfer / GEORGIA BOOTON
Swansea University Author: GEORGIA BOOTON
Abstract
The Swansea positron beam line is a system comprised of a two-pressure-stage nitrogen buffer gas accumulator followed by a third stage trap. This study investigates the ballistic transfer of positrons from the two-stage accumulator to the third stage trap, with the interest to improve the understand...
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Swansea University, Wales, UK
2024
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| Institution: | Swansea University |
| Degree level: | Master of Research |
| Degree name: | MSc by Research |
| Supervisor: | Van der Werf, D., and Madsen, N. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa66095 |
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| Abstract: |
The Swansea positron beam line is a system comprised of a two-pressure-stage nitrogen buffer gas accumulator followed by a third stage trap. This study investigates the ballistic transfer of positrons from the two-stage accumulator to the third stage trap, with the interest to improve the understanding and efficiency of so-called “stacking” technique. The re-trapping efficiency for a single transferhas been categorised by systematically investigating parameters describing the ejected cloud, such as its parallel and transverse energy within the re-trapping region, and its subsequent behaviour within the trap, such as expansion rate and lifetime. A greater than ninety percent transfer efficiency is possible for positrons ejected from the accumulator with a 2.7 eV parallel energy spread, and positron lifetimes in the third stage trap are seen to be greater than 43 s with trap aligned on axis injection of particles and decreases with further off axis transfer injections. A variety of particle manipulation techniques (such as the magnetron manipulation) have been used to systematically study the transfer efficiencies of multiple clouds and the dynamics of these stacked clouds within the trap. |
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| Keywords: |
Physics, positrons, antimatter, Penning trap, trapping charged particles |
| College: |
Faculty of Science and Engineering |