IPAC2015 - List of Authors (Butkowski, L.)

Paper	Title	Page
MOPWA040	Virtual Cavity Probe Generation using Calibrated Forward and Reflected Signals	200
	S. Pfeiffer, V. Ayvazyan, J. Branlard, Ł. Butkowski, H. Schlarb, Ch. Schmidt DESY, Hamburg, Germany R. Rybaniec Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
	The European X-ray free electron laser requires a high-precision control of accelerating fields to ensure a stable photon generation. Its low level radio frequency system, based on the MicroTCA.4 standard, detects the probe, forward and reflected signals for each cavity. While the probe signal is used to control the accelerating fields, a combination of the forward and reflected signals can be used to compute a virtual probe, whose accuracy is comparable to the directly sampled probe. This requires the removal of cross-coupling effects between the forward and reflected signals. This paper presents the precise generation of a virtual probe using an extended method of least squares. The virtual probe can then be used for precise field control in case the probe signal is missing or corrupted. It can also be used to detect any deviation from the nominal probe profile.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA040
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MOPHA028	Operation of Normal Conducting RF Guns with MicroTCA.4	841
	M. Hoffmann, V. Ayvazyan, J. Branlard, Ł. Butkowski, M.K. Grecki, U. Mavrič, M. Omet, S. Pfeiffer, H. Schlarb, Ch. Schmidt DESY, Hamburg, Germany W. Fornal, R. Rybaniec Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland A. Piotrowski FastLogic Sp. z o.o., Łódź, Poland
	During the last half year, the MicroTCA.4 based single cavity LLRF control system was installed and commissioned at several normal conducting facilities at DESY (FLASH RF gun, REGAE, PITZ RF gun, and XFEL RF gun). First tests during the last year show promising results in optimizing the system for high speed digital LLRF feedbacks, i.e. reducing system latency, increasing the internal controller processing speed, testing new control schemes, and optimizing controller parameters. In this contribution we will present results and gained experience from the commissioning phase and the first time period of real operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA028
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MOPHA029	Operation Experiences with the MICROTCA.4-based LLRF Control System at FLASH	844
	M. Omet, V. Ayvazyan, J. Branlard, Ł. Butkowski, M.K. Grecki, M. Hoffmann, F. Ludwig, U. Mavrič, S. Pfeiffer, K.P. Przygoda, H. Schlarb, Ch. Schmidt, H.C. Weddig, B.Y. Yang DESY, Hamburg, Germany W. Cichalewski, D.R. Makowski TUL-DMCS, Łódź, Poland K. Czuba, K. Oliwa, I. Rutkowski, R. Rybaniec, D. Sikora, W. Wierba, M. Żukociński Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland A. Piotrowski FastLogic Sp. z o.o., Łódź, Poland
	The Free-Electron Laser in Hamburg (FLASH) at Deutsches Elektronen-Synchrotron (DESY), Hamburg Germany is a user facility providing ultra-short, femtosecond laser pulses up to the soft X-ray wavelength range. For the precise regulation of the radio frequency (RF) fields within the 60 superconducting cavities, which are organized in 5 RF stations, digital low level RF (LLRF) control systems based on the MTCA.4 standard were implemented in 2013. Until now experiences with failures potentially due to radiation, overheating, and ageing as well as with the general operation of the control systems have been gained. These have a direct impact on the operation and on the performance of FLASH and will allow future improvements. The lessons learned are not only important for FLASH but also in the scope of European X-ray Free-Electron Laser (X-FEL), which will be operated with the same LLRF control system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA029
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TUAD3	LLRF Commissioning of the European XFEL RF Gun and Its First Linac RF Station	1377
	J. Branlard, G. Ayvazyan, V. Ayvazyan, Ł. Butkowski, M.K. Grecki, M. Hoffmann, F. Ludwig, U. Mavrič, M. Omet, S. Pfeiffer, K.P. Przygoda, H. Schlarb, Ch. Schmidt, H.C. Weddig, B.Y. Yang DESY, Hamburg, Germany S. Bou Habib, K. Czuba, M. Grzegrzółka, E. Janas, K. Oliwa, J. Piekarski, K.T. Pozniak, I. Rutkowski, R. Rybaniec, D. Sikora, W. Wierba, L.Z. Zembala, M. Żukociński Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland W. Cichalewski, D.R. Makowski, A. Mielczarek, P. Perek TUL-DMCS, Łódź, Poland A. Piotrowski FastLogic Sp. z o.o., Łódź, Poland
	The European X-ray free electron laser (XFEL) at the Deutsches Elektronen-Synchrotron (DESY), Hamburg Germany is in its construction phase. Approximately a third of the super-conductive cryomodules have been produced and tested. The RF gun is installed since 2013; periods of commissioning are regularly scheduled between installation phases of the rest of the injector. The first linac, L1, consisting of 4 cryomodules powered by one 10 MW klystron is installed and being commissioned. This contribution reports on the installation and preparation work of the low-level radio frequency system (LLRF) to perform the commissioning of the XFEL first components. The commissioning plans, schedule and first results are presented.
	Slides TUAD3 [14.016 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUAD3
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WEPMN032	Microphonic Disturbances Prediction and Compensation in Pulsed Superconducting Accelerators	2997
	R. Rybaniec, L.J. Opalski Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland V. Ayvazyan, Ł. Butkowski, S. Pfeiffer, K.P. Przygoda, H. Schlarb, Ch. Schmidt DESY, Hamburg, Germany
	Accelerators are affected by the cavities detuning variation caused by external mechanical disturbances (microphonics). The paper presents microphonics estimation and prediction methods applicable for superconducting accelerators operating in pulsed mode. A mathematical model is built using the estimates of detuning during previous RF pulses. The model can be used for predictions of disturbances for the future time step and setup of the fast tuners accordingly. The proposed method was successfully verified with measurements conducted at the FLASH linac.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN032
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Virtual Cavity Probe Generation using Calibrated Forward and Reflected Signals

200

S. Pfeiffer, V. Ayvazyan, J. Branlard, Ł. Butkowski, H. Schlarb, Ch. Schmidt
DESY, Hamburg, Germany
R. Rybaniec
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland

The European X-ray free electron laser requires a high-precision control of accelerating fields to ensure a stable photon generation. Its low level radio frequency system, based on the MicroTCA.4 standard, detects the probe, forward and reflected signals for each cavity. While the probe signal is used to control the accelerating fields, a combination of the forward and reflected signals can be used to compute a virtual probe, whose accuracy is comparable to the directly sampled probe. This requires the removal of cross-coupling effects between the forward and reflected signals. This paper presents the precise generation of a virtual probe using an extended method of least squares. The virtual probe can then be used for precise field control in case the probe signal is missing or corrupted. It can also be used to detect any deviation from the nominal probe profile.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA040

Export •

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

MOPHA028

Operation of Normal Conducting RF Guns with MicroTCA.4

841

M. Hoffmann, V. Ayvazyan, J. Branlard, Ł. Butkowski, M.K. Grecki, U. Mavrič, M. Omet, S. Pfeiffer, H. Schlarb, Ch. Schmidt
DESY, Hamburg, Germany
W. Fornal, R. Rybaniec
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
A. Piotrowski
FastLogic Sp. z o.o., Łódź, Poland

During the last half year, the MicroTCA.4 based single cavity LLRF control system was installed and commissioned at several normal conducting facilities at DESY (FLASH RF gun, REGAE, PITZ RF gun, and XFEL RF gun). First tests during the last year show promising results in optimizing the system for high speed digital LLRF feedbacks, i.e. reducing system latency, increasing the internal controller processing speed, testing new control schemes, and optimizing controller parameters. In this contribution we will present results and gained experience from the commissioning phase and the first time period of real operation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA028

Export •

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

MOPHA029

Operation Experiences with the MICROTCA.4-based LLRF Control System at FLASH

844

M. Omet, V. Ayvazyan, J. Branlard, Ł. Butkowski, M.K. Grecki, M. Hoffmann, F. Ludwig, U. Mavrič, S. Pfeiffer, K.P. Przygoda, H. Schlarb, Ch. Schmidt, H.C. Weddig, B.Y. Yang
DESY, Hamburg, Germany
W. Cichalewski, D.R. Makowski
TUL-DMCS, Łódź, Poland
K. Czuba, K. Oliwa, I. Rutkowski, R. Rybaniec, D. Sikora, W. Wierba, M. Żukociński
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
A. Piotrowski
FastLogic Sp. z o.o., Łódź, Poland

The Free-Electron Laser in Hamburg (FLASH) at Deutsches Elektronen-Synchrotron (DESY), Hamburg Germany is a user facility providing ultra-short, femtosecond laser pulses up to the soft X-ray wavelength range. For the precise regulation of the radio frequency (RF) fields within the 60 superconducting cavities, which are organized in 5 RF stations, digital low level RF (LLRF) control systems based on the MTCA.4 standard were implemented in 2013. Until now experiences with failures potentially due to radiation, overheating, and ageing as well as with the general operation of the control systems have been gained. These have a direct impact on the operation and on the performance of FLASH and will allow future improvements. The lessons learned are not only important for FLASH but also in the scope of European X-ray Free-Electron Laser (X-FEL), which will be operated with the same LLRF control system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA029

Export •

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

TUAD3

LLRF Commissioning of the European XFEL RF Gun and Its First Linac RF Station

1377

J. Branlard, G. Ayvazyan, V. Ayvazyan, Ł. Butkowski, M.K. Grecki, M. Hoffmann, F. Ludwig, U. Mavrič, M. Omet, S. Pfeiffer, K.P. Przygoda, H. Schlarb, Ch. Schmidt, H.C. Weddig, B.Y. Yang
DESY, Hamburg, Germany
S. Bou Habib, K. Czuba, M. Grzegrzółka, E. Janas, K. Oliwa, J. Piekarski, K.T. Pozniak, I. Rutkowski, R. Rybaniec, D. Sikora, W. Wierba, L.Z. Zembala, M. Żukociński
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
W. Cichalewski, D.R. Makowski, A. Mielczarek, P. Perek
TUL-DMCS, Łódź, Poland
A. Piotrowski
FastLogic Sp. z o.o., Łódź, Poland

The European X-ray free electron laser (XFEL) at the Deutsches Elektronen-Synchrotron (DESY), Hamburg Germany is in its construction phase. Approximately a third of the super-conductive cryomodules have been produced and tested. The RF gun is installed since 2013; periods of commissioning are regularly scheduled between installation phases of the rest of the injector. The first linac, L1, consisting of 4 cryomodules powered by one 10 MW klystron is installed and being commissioned. This contribution reports on the installation and preparation work of the low-level radio frequency system (LLRF) to perform the commissioning of the XFEL first components. The commissioning plans, schedule and first results are presented.

Slides TUAD3 [14.016 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUAD3

Export •

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

WEPMN032

Microphonic Disturbances Prediction and Compensation in Pulsed Superconducting Accelerators

2997

R. Rybaniec, L.J. Opalski
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
V. Ayvazyan, Ł. Butkowski, S. Pfeiffer, K.P. Przygoda, H. Schlarb, Ch. Schmidt
DESY, Hamburg, Germany

Accelerators are affected by the cavities detuning variation caused by external mechanical disturbances (microphonics). The paper presents microphonics estimation and prediction methods applicable for superconducting accelerators operating in pulsed mode. A mathematical model is built using the estimates of detuning during previous RF pulses. The model can be used for predictions of disturbances for the future time step and setup of the fast tuners accordingly. The proposed method was successfully verified with measurements conducted at the FLASH linac.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEPMN032

Export •

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