Author: Lamb, T.
Paper Title Page
MOPC32 Development Status of Optical Synchronization for the European XFEL 135
 
  • C. Sydlo, M.K. Czwalinna, M. Felber, C. Gerth, T. Lamb, H. Schlarb, S. Schulz, F. Zummack
    DESY, Hamburg, Germany
  • S. Jabłoński
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
  
  Pre­cise tim­ing syn­chro­niza­tion on the fem­tosec­ond timescale is cru­cial for time re­solved ex­per­i­ments at mod­ern free-elec­tron lasers (FELs) like FLASH and the up­com­ing Eu­ro­pean XFEL. The re­quired pre­ci­sion can only be achieved by a laser-based syn­chro­niza­tion sys­tem. The pulsed laser-based scheme at FLASH, based on the dis­tri­b­u­tion of fem­tosec­ond laser pulses over ac­tively sta­bi­lized op­ti­cal fibers, has evolved over the years from a pro­to­type setup to a ma­ture and re­li­able sys­tem. At the same time, the pre­sent im­ple­men­ta­tion serves as pro­to­type for the syn­chro­niza­tion in­fra­struc­ture at the Eu­ro­pean XFEL. Due to a fac­tor of ten in­crease of the length of the ac­cel­er­a­tor and an in­creased num­ber of tim­ing-crit­i­cal sub­sys­tems, new chal­lenges arise. This paper re­ports on the cur­rent de­vel­op­ment progress of the XFEL op­ti­cal syn­chro­niza­tion, dis­cusses major com­pli­ca­tions and their so­lu­tions.  
 
MOPC33 Status of the Fiber Link Stabilization Units at FLASH 139
 
  • F. Zummack, M.K. Czwalinna, M. Felber, T. Lamb, H. Schlarb, S. Schulz, C. Sydlo
    DESY, Hamburg, Germany
  • S. Jabłoński
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
  
  State-of-the-art X-ray pho­ton sci­ence with mod­ern free-elec­tron lasers (FEL) like FLASH and the up­com­ing Eu­ro­pean X-ray Free-Elec­tron Laser Fa­cil­ity (XFEL) re­quires tim­ing with fem­tosec­ond ac­cu­racy. For this pur­pose a so­phis­ti­cated pulsed op­ti­cal syn­chro­niza­tion sys­tem dis­trib­utes pre­cise tim­ing via length-sta­bi­lized fiber links through­out the en­tire FEL. Sta­tions to be syn­chro­nized com­prise bunch ar­rival time mon­i­tors, RF sta­tions and op­ti­cal cross-cor­re­la­tors for ex­ter­nal lasers. The dif­fer­ent re­quire­ments of all those sta­tions have to be met by one op­ti­cal link-sta­bi­liza­tion-unit (LSU) de­sign, com­pen­sat­ing drifts and jit­ter in the dis­tri­b­u­tion sys­tem down to a fs-level. Five years of LSU op­er­a­tion at FLASH have led to nu­mer­ous en­hance­ments re­sult­ing in an elab­o­rate sys­tem. This paper pre­sents these en­hance­ments, their im­pact on syn­chro­niza­tion per­for­mance and the lat­est state of the LSUs.  
 
TUPC33 Femtosecond Stable Laser-to-RF Phase Detection for Optical Synchronization Systems 447
 
  • T. Lamb, M.K. Czwalinna, M. Felber, C. Gerth, H. Schlarb, S. Schulz, C. Sydlo, M. Titberidze, F. Zummack
    DESY, Hamburg, Germany
  • E. Janas
    Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
  • J. Szewiński
    NCBJ, Świerk/Otwock, Poland
  
  Op­ti­cal ref­er­ence dis­tri­b­u­tions have be­come an in­dis­pens­able asset for fem­tosec­ond pre­ci­sion syn­chro­niza­tion of free-elec­tron lasers. At FLASH and for the fu­ture Eu­ro­pean XFEL, laser pulses are dis­trib­uted over large dis­tances in round-trip time sta­bi­lized fibers to all crit­i­cal fa­cil­ity sub-sys­tems. Novel Laser-to-RF phase de­tec­tors will be used to pro­vide ultra phase sta­ble and long-term drift free mi­crowave sig­nals for the ac­cel­er­a­tor RF con­trols. In this paper, we pre­sent the re­cent progress on the de­sign of a fully in­te­grated and en­gi­neered ver­sion of the L2RF phase de­tec­tor, to­gether with first ex­per­i­men­tal re­sults demon­strat­ing so-far un­ri­valed per­for­mance.  
poster icon Poster TUPC33 [18.910 MB]  
 
WEPC32 Past, Present and Future Aspects of Laser-Based Synchronization at FLASH 753
 
  • S. Schulz, M. Bousonville, M.K. Czwalinna, M. Felber, M. Heuer, T. Lamb, J. Müller, P. Peier, S. Ruzin, H. Schlarb, B. Steffen, C. Sydlo, F. Zummack
    DESY, Hamburg, Germany
  • T. Kozak, P. Predki
    TUL-DMCS, Łódź, Poland
  • A. Kuhl
    Uni HH, Hamburg, Germany
  
  Free-elec­tron lasers, like FLASH and the up­com­ing Eu­ro­pean XFEL, are ca­pa­ble of pro­duc­ing XUV and X-ray pulses of a few fem­tosec­onds du­ra­tion. For time-re­solved pump-probe ex­per­i­ments and the ex­ter­nally seeded op­er­a­tion mode it is cru­cial not only to sta­bi­lize the ar­rival time of the elec­tron bunches, but also to achieve a syn­chro­niza­tion ac­cu­racy of ex­ter­nal lasers on the same timescale. This can only be re­al­ized with a laser-based syn­chro­niza­tion in­fra­struc­ture. At FLASH, a pe­ri­odic fem­tosec­ond laser pulse train is trans­mit­ted over ac­tively sta­bi­lized op­ti­cal fibers to the crit­i­cal sub­sys­tems. In this paper we re­port on the pre­sent sta­tus and per­for­mance of the sys­tem, as well as its im­mi­nent up­grades and new in­stal­la­tions. These in­clude the con­nec­tion of FLASH2, elec­tron bunch ar­rival time mon­i­tors for low charges, a new mas­ter laser pulse dis­tri­b­u­tion scheme, all-op­ti­cal syn­chro­niza­tion of the pump-probe laser and ar­rival time mea­sure­ments of the UV pulses on the e-gun pho­to­cath­ode. Along with the com­ing con­nec­tion of the ac­cel­er­a­tion mod­ules to the mas­ter laser and the switch of the low-level hard­ware to the uTCA plat­form, an out­look to im­proved feed­back strate­gies is given.