IPAC2015 - List of Authors (Doebert, S.)

Paper	Title	Page
MOAC1	Awake: the Proof-of-principle R&D Experiment at CERN	34
	P. Muggli MPI, Muenchen, Germany M. Bernardini, T. Bohl, C. Bracco, A.C. Butterworth, S. Cipiccia, H. Damerau, S. Döbert, V. Fedosseev, E. Feldbaumer, E. Gschwendtner, W. Höfle, A. Pardons, A.V. Petrenko, J.S. Schmidt, M. Turner, H. Vincke CERN, Geneva, Switzerland
	The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) is a proof-of-principle R&D experiment at CERN. It is the world’s first proton driven plasma wakefield acceleration experiment, using a high-energy proton bunch to drive a plasma wakefield for electron beam acceleration. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV proton beam bunches from the SPS, which will be sent to a plasma source. An electron beam will be injected into the plasma cell to probe the accelerating wakefield. Challenging modifications in the area and new installations are required for AWAKE. First proton beam to the experiment is expected late 2016. The accelerating electron physics will start late 2017. This paper gives an overview of the project from a physics and engineering point of view, it describes the main activities, the milestones, the organizational set-up for the project management and coordination.
	Slides MOAC1 [21.632 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOAC1
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MOPTY004	Wakefield Monitor Experiments with X-Band Accelerating Structures	947
	R.L. Lillestøl, E. Adli, J. Pfingstner University of Oslo, Oslo, Norway R. Corsini, S. Döbert, W. Farabolini, L. Malina, W. Wuensch CERN, Geneva, Switzerland
	The accelerating structures for CLIC must be aligned with a precision of a few um with respect to the beam trajectory in order to mitigate emittance growth due to transverse wake fields. We report on first results from wake field monitor tests in an X-band structure, with a probe beam at the CLIC Test Facility. The monitors are currently installed in the CLIC Two-Beam Module. In order to fully demonstrate the feasibility of using wakefield monitors for CLIC, the precision of the monitors must be verified using a probe beam while simultaneously filling the structure with high power rf used to drive the accelerating mode. We outline plans to perform such a demonstration in the CLIC Test Facility.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY004
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TUPJE039	Recent Results on the Performance of Cs3Sb Photocathodes in the PHIN RF-Gun	1699
	C. Heßler, E. Chevallay, S. Döbert, V. Fedosseev, I. Martini, M. Martyanov CERN, Geneva, Switzerland
	For the CLIC drive beam a photoinjector option is under study at CERN as an alternative to the thermionic electron gun in the CLIC baseline design. The CLIC drive beam requires a high bunch charge of 8.4 nC and 0.14 ms long trains with 2 ns bunch spacing, which is challenging for a photoinjector. In particular the required long and high intensity laser pulses cause a degradation of the beam quality during the frequency conversion process, which generates the ultra-violet laser beam needed for standard Cs2Te photocathodes. To overcome this issue Cs3Sb cathodes sensitive to green light have been studied at the high-charge PHIN photoinjector since a few years. In this paper recent measurements of fundamental properties of Cs3Sb photocathodes such as quantum efficiency, cathode lifetime and dark current from summer 2014 will be presented, and compared with previous measurements and with the performance of Cs2Te photocathodes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE039
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TUPJE059	Modeling of an Electron Injector for the AWAKE Project	1762
	Ö. Mete, G.X. Xia UMAN, Manchester, United Kingdom R. Apsimon, G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom S. Döbert CERN, Geneva, Switzerland R.B. Fiorito The University of Liverpool, Liverpool, United Kingdom C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Cockcroft Institute Core Grant Particle in cell simulations were performed to characterise an electron injector for AWAKE project in order to provide a tuneable electron beam within a range of specifications required by the plasma wakefield experiments. Tolerances and errors were investigated. These results are presented in this paper alongside with the investigation regarding the beam dynamics implications of the 3GHz travelling wave structure developed for the injector.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE059
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TUPTY003	Study of the Dynamic Response of CLIC Accelerating Structures	2000
	E. Daskalaki NTUA, Athens, Greece S. Döbert, M. Duquenne, H. Mainaud Durand, A.L. Vamvakas CERN, Geneva, Switzerland V. Rude ESGT-CNAM, Le Mans, France
	CLIC is a linear electron-positron collider, 48 km long, consisting of more than 20000 repetitive modules. The target beam size of 1 nm dictates very tight alignment tolerances for the accelerating structures (AS). In order to assess the effect of short-term RF power interruptions (breakdowns or failure modes) on the alignment, the dynamic behaviour of the AS was investigated on the prototype two-beam module. On a dedicated experimental setup, the thermal and mechanical time constant (TC) was monitored as a function of ambient temperature, water flow and power. The experimental results showed that the thermal TC ranged between 4 and 11 minutes and presented strong correlation with the cooling water flow. These results were in very good agreement with the theoretical expectations. The displacement dynamics were found to be comparable with the thermal ones. The study indicates that temperature measurement, which is a fast and easy process, can be used as an indicator of the AS displacement. Moreover, it is shown than the transient response can be efficiently controlled through appropriate regulation of the cooling water flow.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY003
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WEPWA039	The AWAKE Electron Primary Beam Line	2584
	J.S. Schmidt, J. Bauche, B. Biskup, C. Bracco, E. Bravin, S. Döbert, M.A. Fraser, B. Goddard, E. Gschwendtner, L.K. Jensen, O.R. Jones, S. Mazzoni, M. Meddahi, A.V. Petrenko, F.M. Velotti, A.S. Vorozhtsov CERN, Geneva, Switzerland U. Dorda DESY, Hamburg, Germany L. Merminga, V.A. Verzilov TRIUMF, Vancouver, Canada P. Muggli MPI, Muenchen, Germany
	The AWAKE project at CERN is planned to study proton driven plasma wakefield acceleration. The proton beam from the SPS will be used in order to drive wakefields in a 10 m long Rb plasma cell. In the first phase of this experiment, scheduled in 2016, the self-modulation of the proton beam in the plasma will be studied in detail, while in the second phase an external electron beam will be injected into the plasma wakefield to probe the acceleration process. The installation of AWAKE in the former CNGS experimental area and the required optics flexibility define the tight boundary conditions to be fulfilled by the electron beam line design. The transport of low energy (10-20 MeV) bunches of 1.25·10⁹ electrons and the synchronous copropagation with much higher intensity proton bunches (3E11) determines several technological and operational challenges for the magnets and the beam diagnostics. The current status of the electron line layout and the associated equipments are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA039
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Paper

Title

Page

Awake: the Proof-of-principle R&D Experiment at CERN

34

P. Muggli
MPI, Muenchen, Germany
M. Bernardini, T. Bohl, C. Bracco, A.C. Butterworth, S. Cipiccia, H. Damerau, S. Döbert, V. Fedosseev, E. Feldbaumer, E. Gschwendtner, W. Höfle, A. Pardons, A.V. Petrenko, J.S. Schmidt, M. Turner, H. Vincke
CERN, Geneva, Switzerland

The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) is a proof-of-principle R&D experiment at CERN. It is the world’s first proton driven plasma wakefield acceleration experiment, using a high-energy proton bunch to drive a plasma wakefield for electron beam acceleration. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV proton beam bunches from the SPS, which will be sent to a plasma source. An electron beam will be injected into the plasma cell to probe the accelerating wakefield. Challenging modifications in the area and new installations are required for AWAKE. First proton beam to the experiment is expected late 2016. The accelerating electron physics will start late 2017. This paper gives an overview of the project from a physics and engineering point of view, it describes the main activities, the milestones, the organizational set-up for the project management and coordination.

Slides MOAC1 [21.632 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOAC1

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MOPTY004

Wakefield Monitor Experiments with X-Band Accelerating Structures

947

R.L. Lillestøl, E. Adli, J. Pfingstner
University of Oslo, Oslo, Norway
R. Corsini, S. Döbert, W. Farabolini, L. Malina, W. Wuensch
CERN, Geneva, Switzerland

The accelerating structures for CLIC must be aligned with a precision of a few um with respect to the beam trajectory in order to mitigate emittance growth due to transverse wake fields. We report on first results from wake field monitor tests in an X-band structure, with a probe beam at the CLIC Test Facility. The monitors are currently installed in the CLIC Two-Beam Module. In order to fully demonstrate the feasibility of using wakefield monitors for CLIC, the precision of the monitors must be verified using a probe beam while simultaneously filling the structure with high power rf used to drive the accelerating mode. We outline plans to perform such a demonstration in the CLIC Test Facility.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPTY004

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

TUPJE039

Recent Results on the Performance of Cs3Sb Photocathodes in the PHIN RF-Gun

1699

C. Heßler, E. Chevallay, S. Döbert, V. Fedosseev, I. Martini, M. Martyanov
CERN, Geneva, Switzerland

For the CLIC drive beam a photoinjector option is under study at CERN as an alternative to the thermionic electron gun in the CLIC baseline design. The CLIC drive beam requires a high bunch charge of 8.4 nC and 0.14 ms long trains with 2 ns bunch spacing, which is challenging for a photoinjector. In particular the required long and high intensity laser pulses cause a degradation of the beam quality during the frequency conversion process, which generates the ultra-violet laser beam needed for standard Cs2Te photocathodes. To overcome this issue Cs3Sb cathodes sensitive to green light have been studied at the high-charge PHIN photoinjector since a few years. In this paper recent measurements of fundamental properties of Cs3Sb photocathodes such as quantum efficiency, cathode lifetime and dark current from summer 2014 will be presented, and compared with previous measurements and with the performance of Cs2Te photocathodes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE039

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TUPJE059

Modeling of an Electron Injector for the AWAKE Project

1762

Ö. Mete, G.X. Xia
UMAN, Manchester, United Kingdom
R. Apsimon, G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
S. Döbert
CERN, Geneva, Switzerland
R.B. Fiorito
The University of Liverpool, Liverpool, United Kingdom
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Cockcroft Institute Core Grant
Particle in cell simulations were performed to characterise an electron injector for AWAKE project in order to provide a tuneable electron beam within a range of specifications required by the plasma wakefield experiments. Tolerances and errors were investigated. These results are presented in this paper alongside with the investigation regarding the beam dynamics implications of the 3GHz travelling wave structure developed for the injector.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPJE059

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

TUPTY003

Study of the Dynamic Response of CLIC Accelerating Structures

2000

E. Daskalaki
NTUA, Athens, Greece
S. Döbert, M. Duquenne, H. Mainaud Durand, A.L. Vamvakas
CERN, Geneva, Switzerland
V. Rude
ESGT-CNAM, Le Mans, France

CLIC is a linear electron-positron collider, 48 km long, consisting of more than 20000 repetitive modules. The target beam size of 1 nm dictates very tight alignment tolerances for the accelerating structures (AS). In order to assess the effect of short-term RF power interruptions (breakdowns or failure modes) on the alignment, the dynamic behaviour of the AS was investigated on the prototype two-beam module. On a dedicated experimental setup, the thermal and mechanical time constant (TC) was monitored as a function of ambient temperature, water flow and power. The experimental results showed that the thermal TC ranged between 4 and 11 minutes and presented strong correlation with the cooling water flow. These results were in very good agreement with the theoretical expectations. The displacement dynamics were found to be comparable with the thermal ones. The study indicates that temperature measurement, which is a fast and easy process, can be used as an indicator of the AS displacement. Moreover, it is shown than the transient response can be efficiently controlled through appropriate regulation of the cooling water flow.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPTY003

Export •

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

WEPWA039

The AWAKE Electron Primary Beam Line

2584

J.S. Schmidt, J. Bauche, B. Biskup, C. Bracco, E. Bravin, S. Döbert, M.A. Fraser, B. Goddard, E. Gschwendtner, L.K. Jensen, O.R. Jones, S. Mazzoni, M. Meddahi, A.V. Petrenko, F.M. Velotti, A.S. Vorozhtsov
CERN, Geneva, Switzerland
U. Dorda
DESY, Hamburg, Germany
L. Merminga, V.A. Verzilov
TRIUMF, Vancouver, Canada
P. Muggli
MPI, Muenchen, Germany

The AWAKE project at CERN is planned to study proton driven plasma wakefield acceleration. The proton beam from the SPS will be used in order to drive wakefields in a 10 m long Rb plasma cell. In the first phase of this experiment, scheduled in 2016, the self-modulation of the proton beam in the plasma will be studied in detail, while in the second phase an external electron beam will be injected into the plasma wakefield to probe the acceleration process. The installation of AWAKE in the former CNGS experimental area and the required optics flexibility define the tight boundary conditions to be fulfilled by the electron beam line design. The transport of low energy (10-20 MeV) bunches of 1.25·10⁹ electrons and the synchronous copropagation with much higher intensity proton bunches (3E11) determines several technological and operational challenges for the magnets and the beam diagnostics. The current status of the electron line layout and the associated equipments are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPWA039

Export •

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