Paper | Title | Page |
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MOOYGD2 | The AWAKE Experiment in 2021: Performance and Preliminary Results on Electron-Seeding of Self-Modulation | 21 |
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The future programme of the Advanced Wakefield (AWAKE) experiment at CERN relies on the seeded self-modulation of an entire proton bunch, resulting in phase-reproducible micro-bunches. This important milestone was achieved during the 2021 proton run by injecting a short electron bunch ahead of the proton bunch, demonstrating for the first time the electron-seeding of proton bunch self-modulation. This talk describes the programme, performance and preliminary results of the AWAKE experiment in the 2021 proton run, and introduces the program of the 2022 proton run. The observation of electron-seeded self-modulation opens new avenues of exploration which will be studied in 2022, including the effect of a phase difference between the front and the back of a proton bunch and the possibility of reproducibly seeding the hosing instability using the electron beam. | ||
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Slides MOOYGD2 [7.040 MB] | |
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOOYGD2 | |
About • | Received ※ 07 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 16 June 2022 | |
Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
WEPOST039 | Mapping Charge Capture and Acceleration in a Plasma Wakefield of a Proton Bunch Using Variable Emittance Electron Beam Injection | 1780 |
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In the Phase 2 of the AWAKE first experimental run (from May to November 2018), an electron beam was used to probe and test proton-driven wakefield accelera-tion in a rubidium plasma column. The witness electron bunches were produced using an RF-gun equipped with a Cs2Te photocathode illuminated by a tailorable ultrafast ultraviolet (UV) laser pulse. The construction of the UV beam optical system enabled appropriate transverse beam shaping and control of its pulse duration, size, and position on the photocathode, as well as time delay with respect to the ionizing laser pulse that seeds the plasma wakefields in the proton bunches. Variable photocathode illumination provided the required flexibility to produce electron bunches with variable charge, emittance, and injection trajectory into the plasma column. In this work, we analyze the overall charge capture and shot-to-shot reproducibility of the proton-driven plasma wakefield accelerator with various UV illumination and electron bunch injection parameters. | ||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOST039 | |
About • | Received ※ 23 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 29 June 2022 | |
Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
FROXGD1 | A Method for Obtaining 3D Charge Density Distribution of a Self-Modulated Proton Bunch | 3118 |
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The Advanced Wakefield Experiment (AWAKE) at CERN is the first plasma wakefield accelerator experiment to use a proton bunch as driver. The long bunch undergoes seeded self-modulation (SSM) in a 10 m-long plasma. SSM transforms the bunch into a train of short micro-bunches that resonantly drive high-amplitude wakefields. We use optical transition radiation (OTR) and a streak camera to obtain time-resolved images of the bunch transverse charge density distribution in a given plane. In this paper we present a method to obtain 3D images of the bunch by scanning the OTR across the entrance slit of the streak camera. Reconstruction of the 3D distribution is possible because with seeding self-modulation is reproducible*. The 3D images allow for checking the axi-symmetry of SSM and for detecting the possible presence of the non-axi-symmetric hosing instability (HI).
* F. Batsch et al., Phys. Rev. Lett. 126, 164802 (2021). |
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Slides FROXGD1 [4.026 MB] | |
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-FROXGD1 | |
About • | Received ※ 20 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 30 June 2022 | |
Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |