IPAC2018 - List of Authors (Schwarz, M.)

Paper	Title	Page
THPAF042	Improvement of the Longitudinal Beam Transfer from PS to SPS at CERN	3060
	A. Lasheen, H. Damerau, J. Repond, M. Schwarz, E.N. Shaposhnikova CERN, Geneva, Switzerland
	The beam transfer from the Proton Synchrotron (PS) to the Super Proton Synchrotron (SPS) at CERN is a critical process for the production of beams for the Large Hadron Collider (LHC). A bunch-to-bucket transfer is performed with the main drawback that the rf frequency in the SPS (200 MHz) is five times higher than the one in the PS (40 MHz). The PS bunches are therefore shortened non-adiabatically before extraction by applying a fast rf voltage increase (bunch rotation) to fit them into the short rf buckets in the SPS. However, particles with large amplitude of synchrotron oscillations in the PS longitudinal phase space are not properly captured in the SPS. They contribute to losses at the injection plateau and at the start of acceleration in the SPS. In this contribution, we present measurements and simulations performed to identify the source of the uncaptured particles. The tails of the particle distribution were characterized by applying longitudinal shaving during acceleration. Furthermore, the rotated bunch distribution was improved by linearizing the rf voltage using a higher-harmonic rf cavity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF042
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THPAK030	Studies of Longitudinal Dynamics in the Micro-Bunching Instability Using Machine Learning	3277
	T. Boltz, M. Brosi, E. Bründermann, A.-S. Müller, P. Schönfeldt, M. Yan KIT, Karlsruhe, Germany M. Schwarz CERN, Geneva, Switzerland
	The operation of synchrotron light sources with short electron bunches increases the emitted CSR power in the THz frequency range. However, the spatial compression leads to complex longitudinal dynamics, causing the formation of micro-structures in the longitudinal bunch profiles. The fast temporal variation and small scale of these micro-structures put challenging demands on their observation. At the KIT storage ring KARA (KArlsruhe Research Accelerator), diagnostics have been developed allowing direct observation of the dynamics by an electro-optical setup, and indirect observation by measuring the fluctuation of the emitted CSR. In this contribution, we present studies of the micro-structure dynamics on simulated data, obtained using the numerical Vlasov-Fokker-Planck solver Inovesa, and first applications on measured data. To deal with generated data sets in the order of terabytes in size, we apply the machine learning technique k-means to identify the dominant micro-structures in the longitudinal bunch profiles. Following this approach, new insights on the correlation of the CSR power fluctuation to the underlying longitudinal dynamics can be gained.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK030
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THPMF068	Commissioning Status of FLUTE	4229
	A. Malygin, A. Bernhard, E. Bründermann, A. Böhm, S. Funkner, S. Marsching, W. Mexner, A. Mochihashi, A.-S. Müller, M.J. Nasse, G. Niehues, R. Ruprecht, T. Schmelzer, M. Schuh, N.J. Smale, P. Wesolowski, M. Yan KIT, Karlsruhe, Germany I. Križnar Cosylab, Ljubljana, Slovenia M. Schwarz CERN, Geneva, Switzerland
	FLUTE (Ferninfrarot Linac- Und Test-Experiment) will be a new compact versatile linear accelerator at the KIT. Its primary goal is to serve as a platform for a variety of accelerator studies as well as to generate strong ultra-short THz pulses for photon science. The phase I of the project, which includes the RF photo injector providing electrons at beam energy of 7 MeV and a corresponding diagnostics section, is currently being commissioned. In this contribution, we report on the latest progress of the commissioning phase. The status of the gun conditioning will be given, followed by an overview of the RF system and the laser system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF068
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Paper

Title

Page

Improvement of the Longitudinal Beam Transfer from PS to SPS at CERN

3060

A. Lasheen, H. Damerau, J. Repond, M. Schwarz, E.N. Shaposhnikova
CERN, Geneva, Switzerland

The beam transfer from the Proton Synchrotron (PS) to the Super Proton Synchrotron (SPS) at CERN is a critical process for the production of beams for the Large Hadron Collider (LHC). A bunch-to-bucket transfer is performed with the main drawback that the rf frequency in the SPS (200 MHz) is five times higher than the one in the PS (40 MHz). The PS bunches are therefore shortened non-adiabatically before extraction by applying a fast rf voltage increase (bunch rotation) to fit them into the short rf buckets in the SPS. However, particles with large amplitude of synchrotron oscillations in the PS longitudinal phase space are not properly captured in the SPS. They contribute to losses at the injection plateau and at the start of acceleration in the SPS. In this contribution, we present measurements and simulations performed to identify the source of the uncaptured particles. The tails of the particle distribution were characterized by applying longitudinal shaving during acceleration. Furthermore, the rotated bunch distribution was improved by linearizing the rf voltage using a higher-harmonic rf cavity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF042

Export •

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

THPAK030

Studies of Longitudinal Dynamics in the Micro-Bunching Instability Using Machine Learning

3277

T. Boltz, M. Brosi, E. Bründermann, A.-S. Müller, P. Schönfeldt, M. Yan
KIT, Karlsruhe, Germany
M. Schwarz
CERN, Geneva, Switzerland

The operation of synchrotron light sources with short electron bunches increases the emitted CSR power in the THz frequency range. However, the spatial compression leads to complex longitudinal dynamics, causing the formation of micro-structures in the longitudinal bunch profiles. The fast temporal variation and small scale of these micro-structures put challenging demands on their observation. At the KIT storage ring KARA (KArlsruhe Research Accelerator), diagnostics have been developed allowing direct observation of the dynamics by an electro-optical setup, and indirect observation by measuring the fluctuation of the emitted CSR. In this contribution, we present studies of the micro-structure dynamics on simulated data, obtained using the numerical Vlasov-Fokker-Planck solver Inovesa, and first applications on measured data. To deal with generated data sets in the order of terabytes in size, we apply the machine learning technique k-means to identify the dominant micro-structures in the longitudinal bunch profiles. Following this approach, new insights on the correlation of the CSR power fluctuation to the underlying longitudinal dynamics can be gained.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK030

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

THPMF068

Commissioning Status of FLUTE

4229

A. Malygin, A. Bernhard, E. Bründermann, A. Böhm, S. Funkner, S. Marsching, W. Mexner, A. Mochihashi, A.-S. Müller, M.J. Nasse, G. Niehues, R. Ruprecht, T. Schmelzer, M. Schuh, N.J. Smale, P. Wesolowski, M. Yan
KIT, Karlsruhe, Germany
I. Križnar
Cosylab, Ljubljana, Slovenia
M. Schwarz
CERN, Geneva, Switzerland

FLUTE (Ferninfrarot Linac- Und Test-Experiment) will be a new compact versatile linear accelerator at the KIT. Its primary goal is to serve as a platform for a variety of accelerator studies as well as to generate strong ultra-short THz pulses for photon science. The phase I of the project, which includes the RF photo injector providing electrons at beam energy of 7 MeV and a corresponding diagnostics section, is currently being commissioned. In this contribution, we report on the latest progress of the commissioning phase. The status of the gun conditioning will be given, followed by an overview of the RF system and the laser system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF068

Export •

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