IPAC2018 - List of Authors (Blomley, E.)

Paper	Title	Page
WEPAL026	High Repetition Rate, Single-Shot Electro-Optical Monitoring of Longitudinal Electron Bunch Dynamics Using the Linear Array Detector KALYPSO	2216
	G. Niehues, E. Blomley, M. Brosi, E. Bründermann, M. Caselle, S. Funkner, A.-S. Müller, M.J. Nasse, L. Rota, M. Schuh, P. Schönfeldt, M. Weber KIT, Eggenstein-Leopoldshafen, Germany N. Hiller PSI, Villigen PSI, Switzerland
	Funding: This work is funded by the BMBF contract numbers: 05K13VKA and 05K16VKA. High repetition rate diagnostics are required when detecting single-shot electro-optical (EO) bunch profiles. The KIT storage ring KARA (KArlsruhe Research Accelerator) is the first storage ring in the world that has a near-field EO bunch-profile monitor in operation. By imprinting longitudinal electron bunch profiles onto chirped laser pulses, single-shot detection is feasible. However, limitations of available detection systems are challenging: The constraints are either given by the repetition rate or the duration of the consecutive acquisitions. Two strategies can overcome these limitations: Based on the photonic time-stretch method, the ps laser pulses can be stretched to the ns range using km long fibers. The readout with a high-bandwidth oscilloscope then enables a single-shot detection at high repetition rates. The other strategy is the development of dedicated ultra-fast photodetector arrays allowing direct detection of the ps pulses at MHz repetition rates. We developed KALYPSO, a linear detector array with a DAQ allowing to record high data-rates over long time scales. Here, we present recent results of studies of the longitudinal electron bunch dynamics using KALYPSO.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL026
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WEPAL027	Filling Pattern Measurements Using Dead-Time Corrected Single Photon Counting	2219
	B. Kehrer, E. Blomley, M. Brosi, E. Bründermann, A.-S. Müller, M. Schuh, P. Schönfeldt, J.L. Steinmann KIT, Karlsruhe, Germany
	Time-correlated single photon counting (TCSPC) is a versatile tool for various accelerator diagnostics aspects. Amongst others it allows a precise determination of the filling pattern. At the visible light diagnostics port at the Karlsruhe Research Accelerator (KARA), the KIT storage ring, a Single-Photon Avalanche Diode (SPAD) in combination with a histogramming device (PicoHarp) is used. To compensate for possible dead-time effects, a correction scheme was developed and tested successfully. The compensation increases the dynamic range in which accurate measurements are possible and avoids distortion of the measured filling pattern. This contribution presents the experimental setup, as well as a series of benchmark measurements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL027
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WEPAL028	Study of the Influence of the CSR Impedance on the Synchronous Phase Shift at KARA	2223
	P. Schönfeldt, E. Blomley, M. Brosi, E. Bründermann, J. Gethmann, B. Kehrer, A.-S. Müller, A.I. Papash, J.L. Steinmann KIT, Karlsruhe, Germany
	Funding: This work has been supported by the German Federal Ministry of Education and Research (Grant No. 05K16VKA) and the Helmholtz Association (Contract No. VH-NG-320). Measurements of the bunch current dependent synchronous phase shift are a standard method to characterize the impedance of a storage ring. To study this shift, different experimental approaches can be used. In this contribution, we first derive the phase shift caused by the impedance describing the emission of coherent synchrotron radiation (CSR) based on numerical simulations of the longitudinal phase space. The predicted shift is compared to measurement results obtained by time-correlated single photon counting.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL028
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THPMF066	Performance of a Full Scale Superconducting Undulator with 20 mm Period Length at the KIT Synchrotron	4223
	S. Casalbuoni, S. Bauer, E. Blomley, N. Glamann, A.W. Grau, T. Holubek, E. Huttel, D. Saez de Jauregui KIT, Eggenstein-Leopoldshafen, Germany C. Boffo, T.A. Gerhard, M. Turenne, W. Walter Bilfinger Noell GmbH, Wuerzburg, Germany
	Within the collaborative effort between KIT and Bilfinger Noell GmbH the development of a full scale superconducting undulator with 20 mm period length (SCU20) has been completed. This device addresses the reliability and reproducibility aspects of the manufacturing process, allowing for the status of a commercial product. The conduction cooled 1.5 m long coils were characterized in the KIT horizontal test facility CASPER II and later assembled in the final cryostat. The system was extensively tested in the final configuration before installation in the KIT storage ring KARA (Karlsruhe Research Accelerator) to be the source of the NANO beamline in December 2017. Here we present the performance of the device.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF066
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THPMF070	Non-Linear Optics and Low Alpha Operation at the Storage Ring KARA at KIT	4235
	A.I. Papash, E. Blomley, M. Brosi, J. Gethmann, B. Kehrer, A.-S. Müller, M. Schuh, P. Schönfeldt, J.L. Steinmann KIT, Karlsruhe, Germany
	The storage ring Karlsruhe Research Accelerator (KARA) at KIT operate in a wide energy range from 0.5 to 2.5 GeV. Different non-linear effects, in particular, residual octupole components of the magnetic field of the CATACT wiggler at high field level (2.5 T), proximity of the working point to a vertical sextupole resonance Qy=8/3 and weak coupling octupole resonance 2Qx+2Qy=19, high chromaticity, etc. decrease the beam life time. This is because of the reduced dynamic aperture and momentum acceptance for off-momentum particles. A new operation point at high vertical tune Qy=2.81 was tested. For this, injection and ramping tables have been modified. First the values were optimized by simulations, then during beam tests, to minimize betatron tune shaking during beam-energy ramps. It stabilized high-current beams by the fast-feedback system the whole process: injection at 0.5 GeV, ramping, and operation at 1.3 GeV cycles. It essentially improved life time and beam current. In addition, new low-alpha tables have been created and tested, resulting in the reduction of the momentum compaction factor to 10^-4. Short bunch operation at 0.5GeV injection energy was also tested successfully.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF070
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Paper

Title

Page

High Repetition Rate, Single-Shot Electro-Optical Monitoring of Longitudinal Electron Bunch Dynamics Using the Linear Array Detector KALYPSO

2216

G. Niehues, E. Blomley, M. Brosi, E. Bründermann, M. Caselle, S. Funkner, A.-S. Müller, M.J. Nasse, L. Rota, M. Schuh, P. Schönfeldt, M. Weber
KIT, Eggenstein-Leopoldshafen, Germany
N. Hiller
PSI, Villigen PSI, Switzerland

Funding: This work is funded by the BMBF contract numbers: 05K13VKA and 05K16VKA.
High repetition rate diagnostics are required when detecting single-shot electro-optical (EO) bunch profiles. The KIT storage ring KARA (KArlsruhe Research Accelerator) is the first storage ring in the world that has a near-field EO bunch-profile monitor in operation. By imprinting longitudinal electron bunch profiles onto chirped laser pulses, single-shot detection is feasible. However, limitations of available detection systems are challenging: The constraints are either given by the repetition rate or the duration of the consecutive acquisitions. Two strategies can overcome these limitations: Based on the photonic time-stretch method, the ps laser pulses can be stretched to the ns range using km long fibers. The readout with a high-bandwidth oscilloscope then enables a single-shot detection at high repetition rates. The other strategy is the development of dedicated ultra-fast photodetector arrays allowing direct detection of the ps pulses at MHz repetition rates. We developed KALYPSO, a linear detector array with a DAQ allowing to record high data-rates over long time scales. Here, we present recent results of studies of the longitudinal electron bunch dynamics using KALYPSO.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL026

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

WEPAL027

Filling Pattern Measurements Using Dead-Time Corrected Single Photon Counting

2219

B. Kehrer, E. Blomley, M. Brosi, E. Bründermann, A.-S. Müller, M. Schuh, P. Schönfeldt, J.L. Steinmann
KIT, Karlsruhe, Germany

Time-correlated single photon counting (TCSPC) is a versatile tool for various accelerator diagnostics aspects. Amongst others it allows a precise determination of the filling pattern. At the visible light diagnostics port at the Karlsruhe Research Accelerator (KARA), the KIT storage ring, a Single-Photon Avalanche Diode (SPAD) in combination with a histogramming device (PicoHarp) is used. To compensate for possible dead-time effects, a correction scheme was developed and tested successfully. The compensation increases the dynamic range in which accurate measurements are possible and avoids distortion of the measured filling pattern. This contribution presents the experimental setup, as well as a series of benchmark measurements.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL027

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WEPAL028

Study of the Influence of the CSR Impedance on the Synchronous Phase Shift at KARA

2223

P. Schönfeldt, E. Blomley, M. Brosi, E. Bründermann, J. Gethmann, B. Kehrer, A.-S. Müller, A.I. Papash, J.L. Steinmann
KIT, Karlsruhe, Germany

Funding: This work has been supported by the German Federal Ministry of Education and Research (Grant No. 05K16VKA) and the Helmholtz Association (Contract No. VH-NG-320).
Measurements of the bunch current dependent synchronous phase shift are a standard method to characterize the impedance of a storage ring. To study this shift, different experimental approaches can be used. In this contribution, we first derive the phase shift caused by the impedance describing the emission of coherent synchrotron radiation (CSR) based on numerical simulations of the longitudinal phase space. The predicted shift is compared to measurement results obtained by time-correlated single photon counting.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL028

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THPMF066

Performance of a Full Scale Superconducting Undulator with 20 mm Period Length at the KIT Synchrotron

4223

S. Casalbuoni, S. Bauer, E. Blomley, N. Glamann, A.W. Grau, T. Holubek, E. Huttel, D. Saez de Jauregui
KIT, Eggenstein-Leopoldshafen, Germany
C. Boffo, T.A. Gerhard, M. Turenne, W. Walter
Bilfinger Noell GmbH, Wuerzburg, Germany

Within the collaborative effort between KIT and Bilfinger Noell GmbH the development of a full scale superconducting undulator with 20 mm period length (SCU20) has been completed. This device addresses the reliability and reproducibility aspects of the manufacturing process, allowing for the status of a commercial product. The conduction cooled 1.5 m long coils were characterized in the KIT horizontal test facility CASPER II and later assembled in the final cryostat. The system was extensively tested in the final configuration before installation in the KIT storage ring KARA (Karlsruhe Research Accelerator) to be the source of the NANO beamline in December 2017. Here we present the performance of the device.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF066

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THPMF070

Non-Linear Optics and Low Alpha Operation at the Storage Ring KARA at KIT

4235

A.I. Papash, E. Blomley, M. Brosi, J. Gethmann, B. Kehrer, A.-S. Müller, M. Schuh, P. Schönfeldt, J.L. Steinmann
KIT, Karlsruhe, Germany

The storage ring Karlsruhe Research Accelerator (KARA) at KIT operate in a wide energy range from 0.5 to 2.5 GeV. Different non-linear effects, in particular, residual octupole components of the magnetic field of the CATACT wiggler at high field level (2.5 T), proximity of the working point to a vertical sextupole resonance Qy=8/3 and weak coupling octupole resonance 2Qx+2Qy=19, high chromaticity, etc. decrease the beam life time. This is because of the reduced dynamic aperture and momentum acceptance for off-momentum particles. A new operation point at high vertical tune Qy=2.81 was tested. For this, injection and ramping tables have been modified. First the values were optimized by simulations, then during beam tests, to minimize betatron tune shaking during beam-energy ramps. It stabilized high-current beams by the fast-feedback system the whole process: injection at 0.5 GeV, ramping, and operation at 1.3 GeV cycles. It essentially improved life time and beam current. In addition, new low-alpha tables have been created and tested, resulting in the reduction of the momentum compaction factor to 10^-4. Short bunch operation at 0.5GeV injection energy was also tested successfully.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF070

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