| Paper | Title | Page |
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| THPRB018 | Large-Scale Optical Synchronization System of the European XFEL with Femtosecond Precision | 3835 |
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| Femtosecond pulsed optical synchronization systems have evolved over the last few years and are now a mature technique to synchronize FELs. A large-scale femtosecond-precision synchronization system with up to 44 end-stations has been constructed at the European XFEL to meet the FEL synchronization stability requirements. The synchronization system is used to phase-lock various laser systems with femtosecond accuracy, to precisely measure the electron bunch arrival time along the accelerator for fast arrival time feedbacks and to locally phase stabilize the phase of the RF reference signals for the accelerator RF controls on a femtosecond level. The architecture of the large-scale synchronization system and design choices made to achieve the reliability, maintainability and performance requirements are presented together with measurement results from the past year of operation. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB018 | |
| About • | paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019 | |
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| THPRB020 | A Feedback System to Minimize the Electron Bunch Arrival-Time Jitter Between Femtosecond Laser Pulses and Electron Bunches for Laser-Driven Plasma Wakefield Accelerators | 3843 |
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Funding: The work of S. Mattiello is supported by the German Federal Ministry of Education and Research (BMBF) within the Project MAKE-PWA. In a laser driven plasma based particle accelerator a stable synchronization of the electron bunch and of the plasma wake field in the range of less than 2 fs is necessary in order to optimize the acceleration. For this purpose we are developing a new shot to shot feedback system with a time resolution of less than 1 fs*. We plane to generate stable THz pulses by optical rectification of a fraction of the plasma generating high energy laser pulses in a nonlinear lithium niobate crystal. With these pulses we will energy modulate the electron bunches shot to shot before the plasma to achieve the time resolution. In this contribution we will focus on realization aspects of the shot to shot feedback system and the lithium niobate crystal itself. Here we compare different approximations for the modeling of the generation dynamics (second order or first order calculation) and of the dielectric function (influence of the dispersion relation, of the free carries generated by the pump adsorption and their saturation, depletion of the pump) in order to investigate the importance of a detailed description of the optical properties for the THz generation. *The feedback system will be tested at the Accelerator R&D facility SINBAD (Short Innovative Bunches and Accelerators at DESY). |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB020 | |
| About • | paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019 | |
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| THPRB034 | Timing Synchronization System for Beam Injection from the SACLA Linac to the SPring-8 Storage Ring | 3882 |
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| We developed a timing synchronization system for beam injections from the linac of the X-ray free-electron laser (XFEL), SACLA, to the current SPring-8 storage ring. This injection scheme is beneficial for the next upgraded ring, SPring-8-II, where low emittance injection beams is required. The developed timing system aims at synchronizing the timing between the RF frequencies of the two accelerators which do not have a common subharmonic frequency. An important point is to keep the high performance of the current timing system which provides stable XFEL operation at SACLA. For this purpose, we designed and constructed a MicroTCA.4 system comprised of a high-speed ADC and an RF front-end for the synchronization. The RF signal of SACLA is digitized by the ADC whose clock is synchronized to SPring-8. A digital down-converter in the FPGA on the ADC module gives the phase difference instantaneously and a feedback logic applies a frequency modulation (FM) to the master oscillator of SACLA so as to synchronize SACLA with SPring-8. A bench test result showed that the timing jitter between the two frequency at injection timing was 1.2 ps rms, which was sufficient for the required value of 3 ps rms for the beam injection to the ring. In this presentation, we report an overview of the synchronization system, details of the developed electronics and the system performance obtained by a beam injection experiment from SACLA to SPring-8. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB034 | |
| About • | paper received ※ 30 April 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019 | |
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| THPRB107 | A Novel Design of a Laser Phase Monitor for AWA RF Photocathode Electron Gun | 4076 |
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| It is critical to maintain a stable laser phase for RF photocathode electron gun to achieve high beam stability. In order to achieve a higher beam stability for AWA(Argonne Wakefield Accelerator) beamline, a novel laser phase monitor has been designed to allow us to monitor and feedback on. Both the design and its applications at AWA are presented in this paper. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB107 | |
| About • | paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019 | |
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