NAPAC2016 - List of Authors (Muggli, P.)

Paper	Title	Page
WEPOA01	Effect of Proton Bunch Parameter Variation on AWAKE	684
	N. Savard University of Victoria, Victoria BC, Canada P. Muggli MPI, Muenchen, Germany J. Vieira IPFN, Lisbon, Portugal
	In AWAKE, long proton bunches propagate through a plasma, generating wakefields through the self-modulation instability (SMI). The phase velocity of these wakefields changes during the first 4 m of propagation and growth of the SMI, after which it stabilizes at the proton bunch velocity. This means that the ideal injection point for electrons to be accelerated is after 4 m into the plasma. Using the PIC code OSIRIS, we study how small changes in the initial proton bunch parameters (such as charge, radial and longitudinal bunch length, etc) to be expected in the experiment affect the phase velocity of the wakefields, primarily by looking at the difference in the phase of the wakefields at the point of injection (along the bunch and along the plasma) when changing these parameters by a small amount (±5%). We also look for the region of optimal acceleration/focusing for electron injection. Ultimately, it is found that small changes in the initial proton bunch parameters are not expected to significantly impact electron injection experiments in the future.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA01
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WEPOA02	Progress Toward an Experiment at AWAKE*	687
	P. Muggli MPI, Muenchen, Germany
	The AWAKE experimental program is scheduled to start at the end of 2016. The aim of the first experiments is to detect and study the self-modulation instability (SMI) of the long proton bunch ~12cm in a plasma with wakefields of period of ~1.2mm. The occurrence of SMI results in the formation of a charge core surrounded by a halo in the time-integrated images of the proton bunch transverse profile. Transverse profiles are obtained from scintillator screens and from optical transition radiation (OTR). The OTR is time resolved using a ps-resolution streak camera to determine the start of the wakefields along the bunch on a slow time scale (~ns), i.e., the location of the seeding of the SMI generated by the ionizing laser pulse. The modulation period is measured using the faster time scale (~ps). Coherent transition radiation (CTR) is analyzed by a heterodyne system to also yield the modulation frequency. Later experiments will sample the wakefields generated by externally injecting low-energy (~15MeV) electrons expected to be accelerated to the GeV energy level over the 10m-long plasma. Progress toward the completion of the experimental set-up will be presented. *for the AWAKE Collaboration
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA02
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TUA4CO03	Loading of Wakefields in a Plasma Accelerator Section Driven by a Self-Modulated Proton Beam	457
	V.K.B. Olsen, E. Adli University of Oslo, Oslo, Norway P. Muggli MPI-P, München, Germany J. Vieira Instituto Superior Tecnico, Lisbon, Portugal
	Using parameters from the AWAKE project and particle-in-cell simulations we investigate beam loading of a plasma wake driven by a self-modulated proton beam. Addressing the case of injection of an electron witness bunch after the drive beam has already experienced self-modulation in a previous plasma, we optimise witness bunch parameters of size, charge and injection phase to maximise energy gain and minimise relative energy spread and emittance of the accelerated bunch.
	Slides TUA4CO03 [3.103 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUA4CO03
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Paper

Title

Page

Effect of Proton Bunch Parameter Variation on AWAKE

684

N. Savard
University of Victoria, Victoria BC, Canada
P. Muggli
MPI, Muenchen, Germany
J. Vieira
IPFN, Lisbon, Portugal

In AWAKE, long proton bunches propagate through a plasma, generating wakefields through the self-modulation instability (SMI). The phase velocity of these wakefields changes during the first 4 m of propagation and growth of the SMI, after which it stabilizes at the proton bunch velocity. This means that the ideal injection point for electrons to be accelerated is after 4 m into the plasma. Using the PIC code OSIRIS, we study how small changes in the initial proton bunch parameters (such as charge, radial and longitudinal bunch length, etc) to be expected in the experiment affect the phase velocity of the wakefields, primarily by looking at the difference in the phase of the wakefields at the point of injection (along the bunch and along the plasma) when changing these parameters by a small amount (±5%). We also look for the region of optimal acceleration/focusing for electron injection. Ultimately, it is found that small changes in the initial proton bunch parameters are not expected to significantly impact electron injection experiments in the future.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA01

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOA02

Progress Toward an Experiment at AWAKE*

687

P. Muggli
MPI, Muenchen, Germany

The AWAKE experimental program is scheduled to start at the end of 2016. The aim of the first experiments is to detect and study the self-modulation instability (SMI) of the long proton bunch ~12cm in a plasma with wakefields of period of ~1.2mm. The occurrence of SMI results in the formation of a charge core surrounded by a halo in the time-integrated images of the proton bunch transverse profile. Transverse profiles are obtained from scintillator screens and from optical transition radiation (OTR). The OTR is time resolved using a ps-resolution streak camera to determine the start of the wakefields along the bunch on a slow time scale (~ns), i.e., the location of the seeding of the SMI generated by the ionizing laser pulse. The modulation period is measured using the faster time scale (~ps). Coherent transition radiation (CTR) is analyzed by a heterodyne system to also yield the modulation frequency. Later experiments will sample the wakefields generated by externally injecting low-energy (~15MeV) electrons expected to be accelerated to the GeV energy level over the 10m-long plasma. Progress toward the completion of the experimental set-up will be presented.
*for the AWAKE Collaboration

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-WEPOA02

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUA4CO03

Loading of Wakefields in a Plasma Accelerator Section Driven by a Self-Modulated Proton Beam

457

V.K.B. Olsen, E. Adli
University of Oslo, Oslo, Norway
P. Muggli
MPI-P, München, Germany
J. Vieira
Instituto Superior Tecnico, Lisbon, Portugal

Using parameters from the AWAKE project and particle-in-cell simulations we investigate beam loading of a plasma wake driven by a self-modulated proton beam. Addressing the case of injection of an electron witness bunch after the drive beam has already experienced self-modulation in a previous plasma, we optimise witness bunch parameters of size, charge and injection phase to maximise energy gain and minimise relative energy spread and emittance of the accelerated bunch.

Slides TUA4CO03 [3.103 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUA4CO03

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)