IPAC2012 - List of Authors (Hoffmann, M.)

Paper

Title

Page

The European XFEL LLRF System

55

J. Branlard, G. Ayvazyan, V. Ayvazyan, M.K. Grecki, M. Hoffmann, T. Jeżyński, I.M. Kudla, T. Lamb, F. Ludwig, U. Mavrič, S. Pfeiffer, H. Schlarb, Ch. Schmidt, H.C. Weddig, B.Y. Yang
DESY, Hamburg, Germany
P. Barmuta, S. Bou Habib, L. Butkowski, K. Czuba, M. Grzegrzółka, E. Janas, J. Piekarski, I. Rutkowski, D. Sikora, L. Zembala, M. Żukociński
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
W. Cichalewski, K. Gnidzińska, W. Jałmużna, D.R. Makowski, A. Mielczarek, A. Napieralski, P. Perek, A. Piotrowski, T. Pożniak, K.P. Przygoda
TUL-DMCS, Łódź, Poland
S. Korolczuk, J. Szewiński
The Andrzej Soltan Institute for Nuclear Studies, Centre Świerk, Świerk/Otwock, Poland
K. Oliwa, W. Wierba
IFJ-PAN, Kraków, Poland

The European X-ray free electron laser accelerator consists of 800 superconducting cavities grouped in 25 RF stations. The challenges associated with the size and complexity of this accelerator required a high-precision, modular and scalable low level RF (LLRF) system. TheμTCA technology (uTCA) was chosen to support this system and adapted for RF standards. State-of-the-art hardware development in close collaboration with the industry allowed for the system continuity and maintainability. The complete LLRF system design is now in its final phase and the designed hardware was installed and commissioned at FLASH. The uTCA hardware system, measurement results and system performance validation will be shown. Operational strategy and plans for future automation algorithms for performance optimization will also be presented in this paper.

Slides MOOAC01 [12.188 MB]

WEPPD048

Laser Synchronization at REGAE using Phase Detection at an Intermediate Frequency

2624

M. Felber, M. Hoffmann, U. Mavrič, H. Schlarb, S. Schulz
DESY, Hamburg, Germany
W. Jałmużna
TUL-DMCS, Łódź, Poland

A new linear accelerator is being set up for electron diffraction experiments at DESY. This machine, called REGAE (Relativistic Electron Gun for Atomic Exploration) is composed of a photo-cathode gun and a buncher cavity. It uses a single laser system for both, the generation of the electron bunches and for pump-probe experiments. The required timing jitter between the electron bunches and the laser pulses at the experiment is in the order of 10 fs rms. The conventional method for laser synchronization using RF technique to measure phase-jitter in the baseband is susceptible to distortions caused by ground-loops and electro-magnetic interference. At REGAE a new scheme for an RF-based laser synchronization is deployed. It uses a down-converter which mixes a higher harmonic of the laser repetition rate down to an intermediate frequency (IF). The IF is digitized and its phase calculated. This information is used for the feedback controller keeping the laser and the RF synchronized.

Paper	Title	Page
MOOAC01	The European XFEL LLRF System	55
	J. Branlard, G. Ayvazyan, V. Ayvazyan, M.K. Grecki, M. Hoffmann, T. Jeżyński, I.M. Kudla, T. Lamb, F. Ludwig, U. Mavrič, S. Pfeiffer, H. Schlarb, Ch. Schmidt, H.C. Weddig, B.Y. Yang DESY, Hamburg, Germany P. Barmuta, S. Bou Habib, L. Butkowski, K. Czuba, M. Grzegrzółka, E. Janas, J. Piekarski, I. Rutkowski, D. Sikora, L. Zembala, M. Żukociński Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland W. Cichalewski, K. Gnidzińska, W. Jałmużna, D.R. Makowski, A. Mielczarek, A. Napieralski, P. Perek, A. Piotrowski, T. Pożniak, K.P. Przygoda TUL-DMCS, Łódź, Poland S. Korolczuk, J. Szewiński The Andrzej Soltan Institute for Nuclear Studies, Centre Świerk, Świerk/Otwock, Poland K. Oliwa, W. Wierba IFJ-PAN, Kraków, Poland
	The European X-ray free electron laser accelerator consists of 800 superconducting cavities grouped in 25 RF stations. The challenges associated with the size and complexity of this accelerator required a high-precision, modular and scalable low level RF (LLRF) system. TheμTCA technology (uTCA) was chosen to support this system and adapted for RF standards. State-of-the-art hardware development in close collaboration with the industry allowed for the system continuity and maintainability. The complete LLRF system design is now in its final phase and the designed hardware was installed and commissioned at FLASH. The uTCA hardware system, measurement results and system performance validation will be shown. Operational strategy and plans for future automation algorithms for performance optimization will also be presented in this paper.
	Slides MOOAC01 [12.188 MB]

WEPPD048	Laser Synchronization at REGAE using Phase Detection at an Intermediate Frequency	2624
	M. Felber, M. Hoffmann, U. Mavrič, H. Schlarb, S. Schulz DESY, Hamburg, Germany W. Jałmużna TUL-DMCS, Łódź, Poland
	A new linear accelerator is being set up for electron diffraction experiments at DESY. This machine, called REGAE (Relativistic Electron Gun for Atomic Exploration) is composed of a photo-cathode gun and a buncher cavity. It uses a single laser system for both, the generation of the electron bunches and for pump-probe experiments. The required timing jitter between the electron bunches and the laser pulses at the experiment is in the order of 10 fs rms. The conventional method for laser synchronization using RF technique to measure phase-jitter in the baseband is susceptible to distortions caused by ground-loops and electro-magnetic interference. At REGAE a new scheme for an RF-based laser synchronization is deployed. It uses a down-converter which mixes a higher harmonic of the laser repetition rate down to an intermediate frequency (IF). The IF is digitized and its phase calculated. This information is used for the feedback controller keeping the laser and the RF synchronized.