| Paper | Title | Page |
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| WEPAB140 | Second Beam Test and Numerical Investigation of the Imperial College Plasma (Gabor) Lens Prototype | 2943 |
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Funding: STFC through the Imperial Impact Acceleration Account The design of the Laser-hybrid Accelerator for Radiobiological Applications (LhARA) is based on a series of plasma lenses to capture, focus, and select the energy of the ions produced in the laser-target interaction. A second beam test of the first plasma lens prototype, built at the Imperial College London, took place in October 2017 at the Ion Beam Centre of the University of Surrey. 1.4 MeV proton pencil beams were imaged 0.67m downstream of the lens on a scintillator screen over a wide range of settings. On top of the focusing effect, the electron plasma converted pencil beams into rings. The intensity of each ring shows a different degree of modulation along its circumference. Analysis of the results indicates non-uniformity and an off-axis rotation of the electron plasma. The effect on the beam is presented and compared to the results of a simulation of the plasma dynamics and proton beam transport through the lens. A particle-tracking code was used to study the impact of plasma instabilities on the focusing forces produced by the lens. The m = 1 diocotron instability was associated with the formation of rings from the pencil beams. |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB140 | |
| About • | paper received ※ 19 May 2021 paper accepted ※ 29 August 2021 issue date ※ 18 August 2021 | |
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| THPAB359 | Simulations of the Stage 2 FFA Injection Line of LhARA for Evaluating Beam Transport Performance | 4495 |
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| A new, novel facility for radiobiological research, the Laser-hybrid Accelerator for Radiobiological Applications (LhARA), has recently been proposed. LhARA will be a two-stage facility with the first stage employing laser-target acceleration to produce intense proton bunches of energies up to 15 MeV. The second stage will accelerate the beam in an FFA ring up to 127 MeV. Optimal performance of stage 2, however, will require an emittance reduction of the stage 1 beam due to the FFA’s nominal dynamical acceptance. Here, we demonstrate a new optical configuration of LhARA’s stage 1 lattice that will provide this reduced emittance. The profile of the laser-target generated beam is far from an ideal Gaussian, therefore two start-to-end Monte Carlo particle tracking codes have been used to model beam transport performance from the laser-target source through to the end of the stage 2 FFA injection line. The Geant4-based Beam Delivery Simulation (BDSIM) was used to model beam losses and the collimation that is crucial to LhARA’s energy selection system, and General Particle Tracer (GPT) was used to model the space-charge effects that may impact performance given the emittance reduction. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB359 | |
| About • | paper received ※ 19 May 2021 paper accepted ※ 07 July 2021 issue date ※ 18 August 2021 | |
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |