E-Thesis 769 views 230 downloads
Double Rotating Wall Compression of Positron Clouds and Towards Resistive Cooling / Hywel Turner Evans
Swansea University Author: Hywel Turner Evans
DOI (Published version): 10.23889/SUthesis.60070
Abstract
Low energy positron clouds from a buer gas trap have been characterised and compressed by a novel double rotating wall (RW) electric field. A theoretical and experimental study comparing compression due to dipolar single and double RW electric fields is presented, with details of a custom-built func...
| Published: |
Swansea
2022
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Isaac, Aled ; Charlton, Michael |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa60070 |
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| Abstract: |
Low energy positron clouds from a buer gas trap have been characterised and compressed by a novel double rotating wall (RW) electric field. A theoretical and experimental study comparing compression due to dipolar single and double RW electric fields is presented, with details of a custom-built function generator capable of operating on two sets of four, six, and eight-segment electrodes. The installation of a cylindrical Penning trap with two sets of six-segment RW elec-trodes has allowed the implementation of a double RW, which provides a better approximation to the electric potential in the model for independent charged par-ticle compression. A reduction in particle heating has been observed with the double RW, whilst obtaining at least equivalent compression as the single RW, which may in future allow a reduction in the minimum attainable cloud width.Without the use of RW electric fields, optimisations to positron ejection and recapture techniques led to positron clouds being held in a deep, harmonic poten-tial well for over 100 s, enabling time to study RW electric fields and to perform resistive cooling experiments. |
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| Item Description: |
ORCiD identifier: https://orcid.org/0000-0001-6745-4187 |
| Keywords: |
Positron, physics, antimatter, Penning trap, rotating wall, trapped charged particle |
| College: |
Faculty of Science and Engineering |