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Proton Beam Defocusing as a Result of Self-Modulation in Plasma
The AWAKE experiment will use a \SI{400}{GeV/c} proton beam with a longitudinal bunch length of $\sigma_z = 12\,\rm{cm}$ to create and sustain GV/m plasma wakefields over 10 meters . A 12 cm long bunch can only drive strong wakefields in a plasma with $n_{pe} = 7 \times 10^{14}\,\rm{electrons/cm}^3$...
Autores principales: | , , , , |
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Lenguaje: | eng |
Publicado: |
2016
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Materias: | |
Acceso en línea: | https://dx.doi.org/10.18429/JACoW-NAPAC2016-WEPOA09 http://cds.cern.ch/record/2226328 |
_version_ | 1780952414407360512 |
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author | Turner, Marlene Petrenko, Alexey Gschwendtner, Edda Lotov, Konstantin Sosedkin, Alexander |
author_facet | Turner, Marlene Petrenko, Alexey Gschwendtner, Edda Lotov, Konstantin Sosedkin, Alexander |
author_sort | Turner, Marlene |
collection | CERN |
description | The AWAKE experiment will use a \SI{400}{GeV/c} proton beam with a longitudinal bunch length of $\sigma_z = 12\,\rm{cm}$ to create and sustain GV/m plasma wakefields over 10 meters . A 12 cm long bunch can only drive strong wakefields in a plasma with $n_{pe} = 7 \times 10^{14}\,\rm{electrons/cm}^3$ after the self-modulation instability (SMI) developed and microbunches formed, spaced at the plasma wavelength. The fields present during SMI focus and defocus the protons in the transverse plane \cite{SMI}. We show that by inserting two imaging screens downstream the plasma, we can measure the maximum defocusing angle of the defocused protons for plasma densities above $n_{pe} = 5 \times 10^{14}\,\rm{electrons/cm}^{-3}$. Measuring maximum defocusing angles around 1 mrad indirectly proves that SMI developed successfully and that GV/m plasma wakefields were created. In this paper we present numerical studies on how and when the wakefields defocus protons in plasma, the expected measurement results of the two screen diagnostics and the physics we can deduce from it. |
id | cern-2226328 |
institution | Organización Europea para la Investigación Nuclear |
language | eng |
publishDate | 2016 |
record_format | invenio |
spelling | cern-22263282021-05-03T20:28:08Zdoi:10.18429/JACoW-NAPAC2016-WEPOA09http://cds.cern.ch/record/2226328engTurner, MarlenePetrenko, AlexeyGschwendtner, EddaLotov, KonstantinSosedkin, AlexanderProton Beam Defocusing as a Result of Self-Modulation in Plasmaphysics.acc-phAccelerators and Storage RingsThe AWAKE experiment will use a \SI{400}{GeV/c} proton beam with a longitudinal bunch length of $\sigma_z = 12\,\rm{cm}$ to create and sustain GV/m plasma wakefields over 10 meters . A 12 cm long bunch can only drive strong wakefields in a plasma with $n_{pe} = 7 \times 10^{14}\,\rm{electrons/cm}^3$ after the self-modulation instability (SMI) developed and microbunches formed, spaced at the plasma wavelength. The fields present during SMI focus and defocus the protons in the transverse plane \cite{SMI}. We show that by inserting two imaging screens downstream the plasma, we can measure the maximum defocusing angle of the defocused protons for plasma densities above $n_{pe} = 5 \times 10^{14}\,\rm{electrons/cm}^{-3}$. Measuring maximum defocusing angles around 1 mrad indirectly proves that SMI developed successfully and that GV/m plasma wakefields were created. In this paper we present numerical studies on how and when the wakefields defocus protons in plasma, the expected measurement results of the two screen diagnostics and the physics we can deduce from it.The AWAKE experiment will use a 400 GeV/c proton beam with a longitudinal bunch length of sigmq_{z} = 12 cm to create and sustain GV/m plasma wakefields over 10 meters. A 12 cm long bunch can only drive strong wakefields in a plasma with n_{p}e = 7 x 10¹⁴ electrons/cm³ after the self-modulation instability (SMI) developed and microbunches formed, spaced at the plasma wavelength. The fields present during SMI focus and defocus the protons in the transverse plane. We show that by inserting two imaging screens downstream the plasma, we can measure the maximum defocusing angle of the defocused protons for plasma densities above n_{p}e = 5 x10¹⁴ electrons/cm³. Measuring maximum defocusing angles around 1 mrad indirectly proves that SMI developed successfully and that GV/m plasma wakefields were created. In this paper we present numerical studies on how and when the wakefields defocus protons in plasma, the expected measurement results of the two screen diagnostics and the physics we can deduce from it.arXiv:1610.05527NAPAC-2016-WEPOA09oai:cds.cern.ch:22263282016-10-18 |
spellingShingle | physics.acc-ph Accelerators and Storage Rings Turner, Marlene Petrenko, Alexey Gschwendtner, Edda Lotov, Konstantin Sosedkin, Alexander Proton Beam Defocusing as a Result of Self-Modulation in Plasma |
title | Proton Beam Defocusing as a Result of Self-Modulation in Plasma |
title_full | Proton Beam Defocusing as a Result of Self-Modulation in Plasma |
title_fullStr | Proton Beam Defocusing as a Result of Self-Modulation in Plasma |
title_full_unstemmed | Proton Beam Defocusing as a Result of Self-Modulation in Plasma |
title_short | Proton Beam Defocusing as a Result of Self-Modulation in Plasma |
title_sort | proton beam defocusing as a result of self-modulation in plasma |
topic | physics.acc-ph Accelerators and Storage Rings |
url | https://dx.doi.org/10.18429/JACoW-NAPAC2016-WEPOA09 http://cds.cern.ch/record/2226328 |
work_keys_str_mv | AT turnermarlene protonbeamdefocusingasaresultofselfmodulationinplasma AT petrenkoalexey protonbeamdefocusingasaresultofselfmodulationinplasma AT gschwendtneredda protonbeamdefocusingasaresultofselfmodulationinplasma AT lotovkonstantin protonbeamdefocusingasaresultofselfmodulationinplasma AT sosedkinalexander protonbeamdefocusingasaresultofselfmodulationinplasma |