Paper |
Title |
Page |
MOPO038 |
RF Operation Experience at the European XFEL |
109 |
MOOP09 |
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- J. Branlard, V. Ayvazyan, Ł. Butkowski, M.K. Grecki, M. Hierholzer, M.G. Hoffmann, M. Hoffmann, M. Killenberg, D. Kostin, T. Lamb, L. Lilje, U. Mavrič, M. Omet, S. Pfeiffer, R. Rybaniec, H. Schlarb, Ch. Schmidt, N. Shehzad, V. Vogel, N. Walker
DESY, Hamburg, Germany
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After its successful commissioning which took place during the first half of 2017, the European X-ray free electron laser is in now in regular operation delivering photons to users since September 2017. This paper presents an overview on the experience gathered during the first couple of years of operation. In particular, the focus is set on RF operation, maintenance activities, availability and typical failures. A first look on machine performance in terms of RF and beam stability, energy reach, radiation related investigations and microphonics studies will also be presented.
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Slides MOPO038 [2.421 MB]
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DOI • |
reference for this paper
※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO038
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About • |
paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019 |
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MOPO104 |
LLRF R&D Towards CW Operation of the European XFEL |
223 |
SPWR026 |
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- A. Bellandi, V. Ayvazyan, J. Branlard, C. Gumus, S. Pfeiffer, K.P. Przygoda, R. Rybaniec, H. Schlarb, Ch. Schmidt, J.K. Sekutowicz
DESY, Hamburg, Germany
- W. Cichalewski
TUL-DMCS, Łódź, Poland
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The ever growing request for machines with a higher average beam pulse rate and also with a relaxed (< 1 MHz) pulse separation calls for superconducting linacs that operate in Long Pulse (LP) or Continuous Wave (CW) mode. For this purpose the European X-ray Free Electron Laser (European XFEL) could be upgraded to add the ability to run in CW/LP mode. Cryo Module Test Bench (CMTB) is a facility used to perform tests on superconducting cavity cryomodules. Because of the interest in upgrading European XFEL to a CW machine, CMTB is now used to perform studies on XM-3, a 1.3 GHz European XFEL-like cryomodule with modified coupling that is able to run with very high quality factor (QL = 10E7…10E8) values. The RF power source allows running the cavities at gradients larger than 16 MV/m. Because of the QL and gradient values involved in these tests, detuning effects like mechanical resonances and microphonics became more challenging to regulate. The goal is then to determine the appropriate set of parameters for the LLRF control system to keep the error to be less than 0.01° in phase and 0.01% in amplitude.
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DOI • |
reference for this paper
※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO104
|
|
About • |
paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019 |
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TUPO132 |
Implementation of the Beam Loading Compensation Algorithm in the LLRF System of the European XFEL |
594 |
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- Ł. Butkowski, J. Branlard, M. Omet, R. Rybaniec, H. Schlarb, Ch. Schmidt
DESY, Hamburg, Germany
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In the European XFEL, a maximum number of 2700 electron bunches per RF pulse with beam currents up to 4.5mA can be accelerated. Such large beam currents can cause a significant drop of the accelerating gradients, which results in large energy changes across the macro-pulse. But, the electron bunch energies should not deviate from the nominal energy to guarantee stable and reproducible generation of photon pulses for the European XFEL users. To overcome this issue, the Low Level RF system (LLRF) compensates in real-time the beam perturbation using a Beam Loading Compensation algorithm (BLC) minimizing the transient gradient variations. The algorithm takes the charge information obtained from beam diagnostic systems e.g. Beam Position Monitors (BPM) and information from the timing system. The BLC is a part of the LLRF controller implemented in the FPGA. The article presents the implementation of the algorithm in the FPGA and shows the results achieved with the BLC in the European XFEL.
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DOI • |
reference for this paper
※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO132
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About • |
paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019 |
|
Export • |
reference for this paper using
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※ LaTeX,
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