IPAC2014 - List of Authors (Hiller, N.)

Paper	Title	Page
MOPRO063	Studies of Bursting CSR in Multi-bunch Operation at the ANKA Storage Ring	225
	V. Judin, M. Brosi, C.M. Caselle, E. Hertle, N. Hiller, A. Kopmann, A.-S. Müller, M. Schuh, N.J. Smale, J.L. Steinmann, M. Weber KIT, Karlsruhe, Germany
	The ANKA storage ring can generate brilliant coherent synchrotron radiation (CSR) in the THz range due to a dedi- cated low-αc -optics with reduced bunch lengths. At higher electron currents the radiation is not stable, but occurs in powerful bursts caused by micro-bunching instabilities. This intense THz radiation is very attractive for users. However, the reproducibility of the experimental conditions is very low due to those power fluctuations. Systematic studies of bursting CSR in multi-bunch operation were performed with fast THz detectors at ANKA using a dedicated, ultra-fast DAQ-FPGA board. The technique and preliminary results of these studies are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO063
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MOPRO066	Status of FLUTE	231
	M. Schuh, I. Birkel, A. Borysenko, A. Böhm, N. Hiller, E. Huttel, S. Höninger, V. Judin, S. Marsching, A.-S. Müller, A.-S. Müller, A.-S. Müller, S. Naknaimueang, M.J. Nasse, R. Rossmanith, R. Ruprecht, M. Schwarz, M. Weber, P. Wesolowski KIT, Eggenstein-Leopoldshafen, Germany R.W. Aßmann, M. Felber, K. Flöttmann, M. Hoffmann, H. Schlarb DESY, Hamburg, Germany H.-H. Braun, R. Ganter, V. Schlott, L. Stingelin PSI, Villigen PSI, Switzerland
	FLUTE, a new linac-based test facility and THz source is currently being built at the Karlsruhe Institute of Technology (KIT) in collaboration with DESY and PSI. It consists of an RF photo gun and a traveling wave linac accelerating electrons to beam energies of ~41 MeV in the charge range from a few pC up to 3 nC. The electron bunch will then be compressed in a magnetic chicane in the range of 1 - 300 fs, depending on the charge, in order to generate coherent THz radiation with high peak power. An overview of the simulation and hardware status is given in this contribution.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO066
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MOPRO068	Fluctuation of Bunch Length in Bursting CSR: Measurement and Simulation	237
	P. Schönfeldt, A. Borysenko, E. Hertle, N. Hiller, V. Judin, A.-S. Müller, S. Naknaimueang, M. Schuh, M. Schwarz, J.L. Steinmann KIT, Karlsruhe, Germany
	The ANKA electron storage ring of the Karlsruher Institute of Technology (KIT, Germany) is regularly operated in low-alpha mode to produce short bunches for the generation of coherent synchrotron radiation (CSR). This paper evaluates systematic bunch length measurements taken in low-alpha operation of the ANKA storage ring. Above the bursting threshold not only the emission of CSR occurs in bursts, but also a continuous fluctuation of the bunch's length is observed. The measurements were carried out using concurrent multi turn (using a streak camera) as well as single shot (using electro-optical spectral decoding) methods. Furthermore, we compare information obtained on the fluctuation to simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO068
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TUPRI074	First Results of the New Bunch-by-bunch Feedback System at ANKA	1739
	E. Hertle, N. Hiller, E. Huttel, B. Kehrer, A.-S. Müller, A.-S. Müller, N.J. Smale KIT, Eggenstein-Leopoldshafen, Germany M. Höner DELTA, Dortmund, Germany D. Teytelman Dimtel, San Jose, USA
	A new digital three dimensional fast bunch by bunch feedback system has been installed and commissioned at ANKA. Immediate improvements to stored current and lifetime were achieved for normal user operation. For this, the feedback has to be running during the injection and the energy ramp to 2.5 GeV. Additionally, the feedback system was also incorporated into the diagnostic tool-set at ANKA and opened up new possibilities of automated and continuous measurements of certain beam parameters. The system can operate in different modes such as the low alpha operation mode, which has different requirements on the feedback system compared to normal user operation. Results on the various aspects will be presented as well as future improvements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI074
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WEOBB02	Status of Single-shot EOSD Measurement at ANKA	1909
	N. Hiller, A. Borysenko, E. Hertle, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, M.J. Nasse, M. Schuh, P. Schönfeldt, N.J. Smale, J.L. Steinmann KIT, Karlsruhe, Germany P. Peier, B. Steffen DESY, Hamburg, Germany V. Schlott PSI, Villigen PSI, Switzerland
	Funding: This work is funded by the BMBF contract numbers: 05K10VKC, 05K13VKA. ANKA is the first storage ring in the world with a near-field single-shot electro-optical (EO) bunch profile monitor. The method of electro-optical spectral decoding (EOSD) uses the Pockels effect to modulate the longitudinal electron bunch profile onto a long, chirped laser pulse passing through an EO crystal. The laser pulse is then analyzed with a single-shot spectrometer and from the spectral modulation, the temporal modulation can be extracted. The setup has a sub-ps resolution (granularity) and can measure down to bunch lengths of 1.5 ps RMS for bunch charges as low as 30 pC. With this setup it is possible to study longitudinal beam dynamics (e. g. microbunching) occurring during ANKA's low-alpha-operation, an operation mode with compressed bunches to generate coherent synchrotron radiation in the THz range. In addition to measuring the longitudinal bunch profile, long-ranging wake-fields trailing the electron bunch can also be studied, revealing bunch-bunch interactions.
	Slides WEOBB02 [12.753 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEOBB02
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WEPRO002	Studies of Ultrashort THz Pulses at DELTA	1936
	P. Ungelenk, L.-G. Böttger, S. Hilbrich, H. Huck, M. Huck, M. Höner, S. Khan, C. Mai, A. Meyer auf der Heide, R. Molo, H. Rast, A. Schick DELTA, Dortmund, Germany S. Bielawski, C. Evain, M. Le Parquier, E. Roussel, C. Szwaj PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France N. Hiller, V. Judin, J. Raasch, P. Thoma KIT, Karlsruhe, Germany
	Funding: Work supported by the DFG, the BMBF, and the state of NRW. At DELTA, a 1.5-GeV electron storage ring operated as a light source by the Center for Synchrotron Radiation at the TU Dortmund University, coherent ultrashort THz pulses are routinely generated by density-modulated electron bunches. Tracking simulations as well as experimental studies using ultrafast THz detectors and an FT-IR spectrometer aim at understanding the turn-by-turn evolution of the density modulation after an initial laser-electron interaction. Furthermore, intensity-modulated laser pulses are applied to create narrow-band THz radiation. This setup is part of the new short-pulse facility based on coherent harmonic generation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO002
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THPME123	Electro-optical Bunch Length Monitor for FLUTE: Layout and Simulations	3527
	A. Borysenko, E. Hertle, N. Hiller, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, M.J. Nasse, R. Rossmanith, R. Ruprecht, M. Schuh, M. Schwarz, P. Wesolowski KIT, Karlsruhe, Germany B. Steffen DESY, Hamburg, Germany
	Funding: This work is funded by the European Union under contract PITN-GA-2011-289191 A new compact linear accelerator FLUTE is currently under construction at Karlsruhe Institute of Technology (KIT) in collaboration with DESY and PSI. It aims at obtaining femtosecond electron bunches (~1fs - 300 fs) with a wide charge range (1 pC - 3 nC) and requires a precise bunch length diagnostic system. Here we present the layout of a bunch length monitor based on the electro-optic technique of spectral decoding using an Yb-doped fiber laser system (central wavelength 1030 nm) and a GaP crystal. Simulations of the electro-optic signal for different operation modes of FLUTE were performed and main challenges are discussed in this talk. This work is funded by the European Union under contract PITN-GA-2011-289191
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME123
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THPME124	Spectral Analysis of Micro-Bunching Instabilities using Fast THz Detectors	3530
	J.L. Steinmann, E. Hertle, N. Hiller, V. Judin, A.-S. Müller, M. Schuh, P. Schönfeldt, P. Schütze KIT, Karlsruhe, Germany E. Bründermann Ruhr-Universität Bochum, Bochum, Germany
	Micro-bunching instabilities occur at synchrotron light sources when the particle density rises due to compression of the electron bunches. They lead to powerful bursts of coherent synchrotron radiation (CSR) in the THz range at the cost of very unstable intensity and spectral properties, highly fluctuating on a millisecond time scale. For interferometry this changing source demands a long averaging time to achieve a reasonably high signal-to-noise ratio or balancing by the use of an additional reference detector. In this study we present measurements taken by a Martin-Puplett-interferometer in the bursting regime with ultra-fast THz-detectors.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME124
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Paper

Title

Page

Studies of Bursting CSR in Multi-bunch Operation at the ANKA Storage Ring

225

V. Judin, M. Brosi, C.M. Caselle, E. Hertle, N. Hiller, A. Kopmann, A.-S. Müller, M. Schuh, N.J. Smale, J.L. Steinmann, M. Weber
KIT, Karlsruhe, Germany

The ANKA storage ring can generate brilliant coherent synchrotron radiation (CSR) in the THz range due to a dedi- cated low-αc -optics with reduced bunch lengths. At higher electron currents the radiation is not stable, but occurs in powerful bursts caused by micro-bunching instabilities. This intense THz radiation is very attractive for users. However, the reproducibility of the experimental conditions is very low due to those power fluctuations. Systematic studies of bursting CSR in multi-bunch operation were performed with fast THz detectors at ANKA using a dedicated, ultra-fast DAQ-FPGA board. The technique and preliminary results of these studies are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO063

Export •

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

MOPRO066

Status of FLUTE

231

M. Schuh, I. Birkel, A. Borysenko, A. Böhm, N. Hiller, E. Huttel, S. Höninger, V. Judin, S. Marsching, A.-S. Müller, A.-S. Müller, A.-S. Müller, S. Naknaimueang, M.J. Nasse, R. Rossmanith, R. Ruprecht, M. Schwarz, M. Weber, P. Wesolowski
KIT, Eggenstein-Leopoldshafen, Germany
R.W. Aßmann, M. Felber, K. Flöttmann, M. Hoffmann, H. Schlarb
DESY, Hamburg, Germany
H.-H. Braun, R. Ganter, V. Schlott, L. Stingelin
PSI, Villigen PSI, Switzerland

FLUTE, a new linac-based test facility and THz source is currently being built at the Karlsruhe Institute of Technology (KIT) in collaboration with DESY and PSI. It consists of an RF photo gun and a traveling wave linac accelerating electrons to beam energies of ~41 MeV in the charge range from a few pC up to 3 nC. The electron bunch will then be compressed in a magnetic chicane in the range of 1 - 300 fs, depending on the charge, in order to generate coherent THz radiation with high peak power. An overview of the simulation and hardware status is given in this contribution.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO066

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MOPRO068

Fluctuation of Bunch Length in Bursting CSR: Measurement and Simulation

237

P. Schönfeldt, A. Borysenko, E. Hertle, N. Hiller, V. Judin, A.-S. Müller, S. Naknaimueang, M. Schuh, M. Schwarz, J.L. Steinmann
KIT, Karlsruhe, Germany

The ANKA electron storage ring of the Karlsruher Institute of Technology (KIT, Germany) is regularly operated in low-alpha mode to produce short bunches for the generation of coherent synchrotron radiation (CSR). This paper evaluates systematic bunch length measurements taken in low-alpha operation of the ANKA storage ring. Above the bursting threshold not only the emission of CSR occurs in bursts, but also a continuous fluctuation of the bunch's length is observed. The measurements were carried out using concurrent multi turn (using a streak camera) as well as single shot (using electro-optical spectral decoding) methods. Furthermore, we compare information obtained on the fluctuation to simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO068

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TUPRI074

First Results of the New Bunch-by-bunch Feedback System at ANKA

1739

E. Hertle, N. Hiller, E. Huttel, B. Kehrer, A.-S. Müller, A.-S. Müller, N.J. Smale
KIT, Eggenstein-Leopoldshafen, Germany
M. Höner
DELTA, Dortmund, Germany
D. Teytelman
Dimtel, San Jose, USA

A new digital three dimensional fast bunch by bunch feedback system has been installed and commissioned at ANKA. Immediate improvements to stored current and lifetime were achieved for normal user operation. For this, the feedback has to be running during the injection and the energy ramp to 2.5 GeV. Additionally, the feedback system was also incorporated into the diagnostic tool-set at ANKA and opened up new possibilities of automated and continuous measurements of certain beam parameters. The system can operate in different modes such as the low alpha operation mode, which has different requirements on the feedback system compared to normal user operation. Results on the various aspects will be presented as well as future improvements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI074

Export •

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

WEOBB02

Status of Single-shot EOSD Measurement at ANKA

1909

N. Hiller, A. Borysenko, E. Hertle, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, M.J. Nasse, M. Schuh, P. Schönfeldt, N.J. Smale, J.L. Steinmann
KIT, Karlsruhe, Germany
P. Peier, B. Steffen
DESY, Hamburg, Germany
V. Schlott
PSI, Villigen PSI, Switzerland

Funding: This work is funded by the BMBF contract numbers: 05K10VKC, 05K13VKA.
ANKA is the first storage ring in the world with a near-field single-shot electro-optical (EO) bunch profile monitor. The method of electro-optical spectral decoding (EOSD) uses the Pockels effect to modulate the longitudinal electron bunch profile onto a long, chirped laser pulse passing through an EO crystal. The laser pulse is then analyzed with a single-shot spectrometer and from the spectral modulation, the temporal modulation can be extracted. The setup has a sub-ps resolution (granularity) and can measure down to bunch lengths of 1.5 ps RMS for bunch charges as low as 30 pC. With this setup it is possible to study longitudinal beam dynamics (e. g. microbunching) occurring during ANKA's low-alpha-operation, an operation mode with compressed bunches to generate coherent synchrotron radiation in the THz range. In addition to measuring the longitudinal bunch profile, long-ranging wake-fields trailing the electron bunch can also be studied, revealing bunch-bunch interactions.

Slides WEOBB02 [12.753 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEOBB02

Export •

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

WEPRO002

Studies of Ultrashort THz Pulses at DELTA

1936

P. Ungelenk, L.-G. Böttger, S. Hilbrich, H. Huck, M. Huck, M. Höner, S. Khan, C. Mai, A. Meyer auf der Heide, R. Molo, H. Rast, A. Schick
DELTA, Dortmund, Germany
S. Bielawski, C. Evain, M. Le Parquier, E. Roussel, C. Szwaj
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
N. Hiller, V. Judin, J. Raasch, P. Thoma
KIT, Karlsruhe, Germany

Funding: Work supported by the DFG, the BMBF, and the state of NRW.
At DELTA, a 1.5-GeV electron storage ring operated as a light source by the Center for Synchrotron Radiation at the TU Dortmund University, coherent ultrashort THz pulses are routinely generated by density-modulated electron bunches. Tracking simulations as well as experimental studies using ultrafast THz detectors and an FT-IR spectrometer aim at understanding the turn-by-turn evolution of the density modulation after an initial laser-electron interaction. Furthermore, intensity-modulated laser pulses are applied to create narrow-band THz radiation. This setup is part of the new short-pulse facility based on coherent harmonic generation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO002

Export •

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

THPME123

Electro-optical Bunch Length Monitor for FLUTE: Layout and Simulations

3527

A. Borysenko, E. Hertle, N. Hiller, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, M.J. Nasse, R. Rossmanith, R. Ruprecht, M. Schuh, M. Schwarz, P. Wesolowski
KIT, Karlsruhe, Germany
B. Steffen
DESY, Hamburg, Germany

Funding: This work is funded by the European Union under contract PITN-GA-2011-289191
A new compact linear accelerator FLUTE is currently under construction at Karlsruhe Institute of Technology (KIT) in collaboration with DESY and PSI. It aims at obtaining femtosecond electron bunches (~1fs - 300 fs) with a wide charge range (1 pC - 3 nC) and requires a precise bunch length diagnostic system. Here we present the layout of a bunch length monitor based on the electro-optic technique of spectral decoding using an Yb-doped fiber laser system (central wavelength 1030 nm) and a GaP crystal. Simulations of the electro-optic signal for different operation modes of FLUTE were performed and main challenges are discussed in this talk. This work is funded by the European Union under contract PITN-GA-2011-289191

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME123

Export •

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

THPME124

Spectral Analysis of Micro-Bunching Instabilities using Fast THz Detectors

3530

J.L. Steinmann, E. Hertle, N. Hiller, V. Judin, A.-S. Müller, M. Schuh, P. Schönfeldt, P. Schütze
KIT, Karlsruhe, Germany
E. Bründermann
Ruhr-Universität Bochum, Bochum, Germany

Micro-bunching instabilities occur at synchrotron light sources when the particle density rises due to compression of the electron bunches. They lead to powerful bursts of coherent synchrotron radiation (CSR) in the THz range at the cost of very unstable intensity and spectral properties, highly fluctuating on a millisecond time scale. For interferometry this changing source demands a long averaging time to achieve a reasonably high signal-to-noise ratio or balancing by the use of an additional reference detector. In this study we present measurements taken by a Martin-Puplett-interferometer in the bursting regime with ultra-fast THz-detectors.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME124

Export •

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