TUBL —  Time Resolve Diagnostics and Synchronization   (13-Sep-16   11:00—13:00)
Chair: M. Ferianis, Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
Paper Title Page
Beam Diagnostics Challenges in Plasma Wakefield Acceleration  
  • J. Osterhoff
    DESY, Hamburg, Germany
  The field of particle acceleration in plasma wakes has seen remarkable progress in recent years. These days, acceleration gradients in excess of 10 GV/m can be readily achieved using either ultra-short intense laser pulses or particle beams as wake drivers. With the advent of first multi-GeV electron beams from plasma and a general trend towards improved reproducibility, beam quality and control over the involved processes, plasma-acceleration techniques are starting to draw considerable interest in the traditional accelerator community. Part of this attention is based on the extreme beam properties obtainable with plasma, such as femtosecond duration and sub-micron normalized transverse emittance, which pose significant obstacles for beam characterization and require cutting-edge detection concepts. In addition, the conservation of these characteristics during beam transport is complicated by ~mm beta functions at the plasma exit in combination with correlated energy spreads typically on a percent level. This presentation will give an introduction into the field of plasma wakefield acceleration and provide an overview about challenges in diagnosing the generated beams.  
slides icon Slides TUBL01 [17.451 MB]  
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Temporal Profile Measurements of Relativistic Electron Bunch Based on Wakefield Generation  
  • S. Bettoni, P. Craievich, M. Pedrozzi
    PSI, Villigen PSI, Switzerland
  • A.A. Lutman
    SLAC, Menlo Park, California, USA
  A full characterization of the beam longitudinal phase space is crucial for the optimization of the performances of Free Electron Laser facilities, which require very short bunches to reach the time resolution for experiments of physics, biology and material science. We studied a novel approach to perform time-resolved measurements of a relativistic electron bunch based on the self-transverse wakefield interaction of the beam itself passing off-axis through a dielectric-lined or corrugated waveguide. The method is passive, can reach sub-fs resolution, and does not suffer of jitter issues. The main limitation is the poor resolution at the head of the bunch. We present simulations and a proof-of-principle experiment carried out at the SwissFEL injector test facility as well.  
slides icon Slides TUBL02 [8.088 MB]  
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TUBL03 Synchronous Laser-Microwave Network for Attosecond-Resolution Photon Science 286
  • K. Shafak, F.X. Kärtner, A. Kalaydzhyan, O.D. Mücke, W. Wang, M. Xin
    CFEL, Hamburg, Germany
  • F.X. Kärtner, M.Y. Peng, M. Xin
    MIT, Cambridge, Massachusetts, USA
  Funding: This work was supported by the Center for Free-Electron Laser Science at Deutsches Elektronen-Synchrotron, a research center of the Helmholtz Association in Germany.
Next-generation photon-science facilities such as X-ray free-electron lasers (X-FELs)* and intense-laser beamline centers** are emerging world-wide with the goal of generating sub-fs X-ray pulses with unprecedented brightness to capture ultrafast chemical and physical phenomena with sub-atomic spatiotemporal resolution. The only obstacle preventing this long-standing scientific dream to come true is a high- precision timing distribution system*** synchronizing various microwave and optical sub-sources across multi-km distances which is required for seeded X-FELs and attosecond pump-probe experiments. Here, we present, for the first time, a synchronous laser-microwave network that will enable attosecond precision photon science facilities. By developing new ultrafast metrological timing devices and carefully balancing fiber nonlinearities and fundamental noise contributions, we have achieved timing stabilization of a 4.7 km fiber network with 580 attosecond precision over 52 hours. Furthermore, we have realized a complete laser-microwave network incorporating two mode-locked lasers and one microwave source with total 950 attosecond jitter integrated from 1 microsecond to 18 hours.
*J. Stohr, LCLS-II Conceptual Design Report. No. SLAC-R-978. (SLAC, 2011).
**G. Mourou, T. Tajima, Optics & Photonics News 22, 47 (2011).
***J. Kim, et al., Nat. Photonics 2(12), 733-736 (2008).
slides icon Slides TUBL03 [11.692 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUBL03  
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TUBL04 Electro-Optical Methods for Multipurpose Diagnostics 290
  • R. Pompili, M.P. Anania, M. Bellaveglia, F.G. Bisesto, E. Chiadroni, A. Curcio, D. Di Giovenale, G. Di Pirro, M. Ferrario
    INFN/LNF, Frascati (Roma), Italy
  • A. Cianchi
    INFN-Roma II, Roma, Italy
  • A. Zigler
    The Hebrew University of Jerusalem, The Racah Institute of Physics, Jerusalem, Israel
  Electro-optic sampling (EOS) based temporal diagnostics allows to precisely measure the temporal profile of electron bunches with resolution of about 50 fs in a non-destructive and single-shot way. At SPARC_LAB we adopted the EOS in very different experimental fields. We measured for the first time the longitudinal profile of a train of multiple bunches at THz repetition rate, as the one required for resonant Plasma Wakefield Acceleration (PWFA) in a single-shot and non-intercepting way. By means of the EOS we demonstrated a new hybrid compression scheme that is able to provide ultra-short bunches (<90 fs) with ultra-low (<20 fs) timing-jitter relative to the EOS laser system. Furthermore, we recently developed an EOS system in order to provide temporal and energy measurements in a very noisy and harsh environment: electron beams ejected by the interaction of high-intensity (hundreds TW class) ultra-short (35fs) laser pulses with solid targets by means of the so-called Target Normal Sheath Acceleration (TNSA) method.  
slides icon Slides TUBL04 [2.183 MB]  
DOI • reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-TUBL04  
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