Hydrodynamic optical-field-ionized plasma waveguides for laser plasma accelerators
<p>This thesis documents the experimental development of low-density hydrodynamic optical-field-ionized (HOFI) plasma channels. Results from two experiments are presented; the first, a proof of concept experiment, performed in Oxford, demonstrating for the first time that the formation of low-...
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| Format: | Thesis |
| Language: | English |
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2018
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| _version_ | 1797087817533227008 |
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| author | Shalloo, R |
| author2 | Hooker, S |
| author_facet | Hooker, S Shalloo, R |
| author_sort | Shalloo, R |
| collection | OXFORD |
| description | <p>This thesis documents the experimental development of low-density hydrodynamic optical-field-ionized (HOFI) plasma channels. Results from two experiments are presented; the first, a proof of concept experiment, performed in Oxford, demonstrating for the first time that the formation of low-density (&Tilde;10<sup>17</sup> cm<sup>-3</sup>) hydrodynamic plasma channels was possible using optical-field-ionization. The second experiment, performed at Astra-Gemini TA2, aimed to demonstrate the generation of low-density axicon-formed HOFI plasma waveguides and subsequently to demonstrate high-intensity guiding in those waveguides at the highest available repetition rate.</p> <p>In the Oxford experiments, short (2-4mm) HOFI plasma channels were generated in hydrogen with a spherical lens and probed with longitudinal interferometry. The channels had on-axis densities between 1.6 × 10<sup>17</sup> cm<sup>-3</sup> and 1 × 10<sup>18</sup> cm<sup>-3</sup> and matched spot sizes of order 30μm to 60μm. A computational investigation into the guiding properties of the measured plasma channels indicated that they would be suitable as plasma waveguides.</p> <p>In the experiments at Astra-Gemini TA2, HOFI plasma channels up to 16mm in length were generated in hydrogen using an axicon. These were probed with both longitudinal and transverse interferometry and had on-axis densities as low as 2 × 10<sup>17</sup> cm<sup>-3</sup> . These waveguides were subsequently used to successfully guide high-intensity (>10<sup>17</sup> W cm<sup>-2</sup>) pulses over the full 16mm or 14.5 Rayleigh ranges, with a maximum throughput of 60 % observed for the higher intensities. The variation in guiding with pressure and with guided beam intensity was investigated experimentally. It was found that the high-intensity guided pulse modified the HOFI plasma channel, with the result of increasing the relative throughput of the guided beam.</p> |
| first_indexed | 2024-03-07T02:41:04Z |
| format | Thesis |
| id | oxford-uuid:aa7a03d0-2d64-423f-be42-40e01479d312 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:41:04Z |
| publishDate | 2018 |
| record_format | dspace |
| spelling | oxford-uuid:aa7a03d0-2d64-423f-be42-40e01479d3122022-03-27T03:15:21ZHydrodynamic optical-field-ionized plasma waveguides for laser plasma acceleratorsThesishttp://purl.org/coar/resource_type/c_db06uuid:aa7a03d0-2d64-423f-be42-40e01479d312Accelerator physicsLaser Plasma PhysicsPlasma PhysicsEnglishORA Deposit2018Shalloo, RHooker, SWark, JCros, B<p>This thesis documents the experimental development of low-density hydrodynamic optical-field-ionized (HOFI) plasma channels. Results from two experiments are presented; the first, a proof of concept experiment, performed in Oxford, demonstrating for the first time that the formation of low-density (&Tilde;10<sup>17</sup> cm<sup>-3</sup>) hydrodynamic plasma channels was possible using optical-field-ionization. The second experiment, performed at Astra-Gemini TA2, aimed to demonstrate the generation of low-density axicon-formed HOFI plasma waveguides and subsequently to demonstrate high-intensity guiding in those waveguides at the highest available repetition rate.</p> <p>In the Oxford experiments, short (2-4mm) HOFI plasma channels were generated in hydrogen with a spherical lens and probed with longitudinal interferometry. The channels had on-axis densities between 1.6 × 10<sup>17</sup> cm<sup>-3</sup> and 1 × 10<sup>18</sup> cm<sup>-3</sup> and matched spot sizes of order 30μm to 60μm. A computational investigation into the guiding properties of the measured plasma channels indicated that they would be suitable as plasma waveguides.</p> <p>In the experiments at Astra-Gemini TA2, HOFI plasma channels up to 16mm in length were generated in hydrogen using an axicon. These were probed with both longitudinal and transverse interferometry and had on-axis densities as low as 2 × 10<sup>17</sup> cm<sup>-3</sup> . These waveguides were subsequently used to successfully guide high-intensity (>10<sup>17</sup> W cm<sup>-2</sup>) pulses over the full 16mm or 14.5 Rayleigh ranges, with a maximum throughput of 60 % observed for the higher intensities. The variation in guiding with pressure and with guided beam intensity was investigated experimentally. It was found that the high-intensity guided pulse modified the HOFI plasma channel, with the result of increasing the relative throughput of the guided beam.</p> |
| spellingShingle | Accelerator physics Laser Plasma Physics Plasma Physics Shalloo, R Hydrodynamic optical-field-ionized plasma waveguides for laser plasma accelerators |
| title | Hydrodynamic optical-field-ionized plasma waveguides for laser plasma accelerators |
| title_full | Hydrodynamic optical-field-ionized plasma waveguides for laser plasma accelerators |
| title_fullStr | Hydrodynamic optical-field-ionized plasma waveguides for laser plasma accelerators |
| title_full_unstemmed | Hydrodynamic optical-field-ionized plasma waveguides for laser plasma accelerators |
| title_short | Hydrodynamic optical-field-ionized plasma waveguides for laser plasma accelerators |
| title_sort | hydrodynamic optical field ionized plasma waveguides for laser plasma accelerators |
| topic | Accelerator physics Laser Plasma Physics Plasma Physics |
| work_keys_str_mv | AT shalloor hydrodynamicopticalfieldionizedplasmawaveguidesforlaserplasmaaccelerators |