Beam Position Monitoring of Multi-bunch Electron Beams at the FLASH Free Electron Laser
177
N. Baboi, H.T. Duhme, B. Lorbeer
DESY, Hamburg, Germany
The superconducting FLASH user facility (Free electron LASer in Hamburg) accelerates 10 electron bunch trains per second, which are mostly used to produce high brilliance XUV and soft X-ray pulses. Each train usually contains up to 600 electron bunches with a typical charge between 100 pC and 1 nC and a minimum bunch spacing of 1 us. Various types of beam position monitors (BPM) are built in three electron beam lines, having a single bunch resolution of 2-100 um rms. This paper presents multi-bunch position measurements for various types of BPMs and built in at various locations. The dependency of the resolution on the beam offset is also shown.
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Requirements and Design for the PETRA IV Fast Orbit Feedback System
343
S.H. Mirza, A. Aloev, H.T. Duhme, B. Dursun, A. Eichler, S. Jabłoński, J. Klute, F. Ludwig, S. Pfeiffer, H. Schlarb, B. Szczepanski
DESY, Hamburg, Germany
G. Rehm
HZB, Berlin, Germany
PETRA IV is the upcoming low-emittance, 6 GeV, fourth- generation light source at DESY Hamburg. It is based upon a six-bend achromat lattice with additional beamlines as compared to PETRA III. Stringent stability of the electron beam orbit in the ring will be required to achieve diffraction- limited photon beam quality. In this regard, the requirements and the proposed topology of the global orbit feedback system are discussed for expected perturbations. An initial analysis based upon system requirements, design and modelling of the subsystems of the orbit feedback system is also presented
B. Lorbeer, H.T. Duhme, I. Krouptchenkov, T. Lensch, D. Lipka, S. Vilcins, M. Werner
DESY, Hamburg, Germany
The SINBAD(Short and INnovative Bunches and Accelerators at DESY ) R&D accelerator is planned for studying new concepts for high gradient electron beam acceleration and the generation of ultra-short electron bunches. The accelerator called ARES(Accelerator Research Experiment At DESY) is composed of S-band accelerating structures. In order to achieve the goal of very short electron bunches the electron beam charges generated in the RF Gun can vary in a range from 1nC down to 500fC. In order to measure the beam position with good resolution at the small charge end of 500fC a new cavity BPM(beam position monitor) has been developed. One key component in the BPM system is the custom RF electronics to meet the resolution requirements in the entire charge range. The entire BPM system with a focus on the system design requirements and the utca based RF electronics are presented in this paper.
Conceptual Design of the Transverse Multi-Bunch Feedback for the Synchrotron Radiation Source PETRA IV
488
S. Jabłoński, H.T. Duhme, B. Dursun, J. Klute, S.H. Mirza, S. Pfeiffer, H. Schlarb
DESY, Hamburg, Germany
PETRA IV will be a new, fourth-generation, high-brilliance synchrotron radiation source in the hard X-ray range. To keep the emittance low at high beam current an active feedback system to damp transverse multi-bunch instabilities is required. The particular challenge to the system is the very low-noise, while maintaining high bandwidth, which is defined by the 2 ns bunch spacing. In this paper, we present the conceptual design of the transverse multi-bunch feedback (T-MBFB) system and technical challenges to fulfill the performance require-ments. An overview is given on the hardware and the method for detecting and damping the coupled-bunch oscillations. Using modern high-speed ADCs enables direct sampling of pulses from beam pick-ups, which removes the necessity for down-converters. Powerful digital signal processing allows not only for the effective feedback implementation, but also for developing versa-tile tools for the machine diagnostics.