Author: Xiang, D.
Paper Title Page
WEXB01 Recent Advances and New Techniques in Visualization of Ultra-short Relativistic Electron Bunches 2091
  • D. Xiang
    SLAC, Menlo Park, California, USA
  Funding: Work supported by U.S. DOE under Contract No. DE-AC02-76SF00515.
This talk will address advances in the measurement of ultra-short relativistic bunches at femtosecond frontier in high-energy x-ray free-electron lasers (FELs). In general, this presentation will discuss several recently proposed novel techniques (i.e. mapping z exactly to delta * and x **, optical oscilloscope ***, etc.) that are capable of breaking the femtosecond time barrier in measurements of ultrashort bunches. In particular, this presentation will report on the all-optical, time-resolved method to probe beam longitudinal phase space with femtosecond time scale and 10-5 energy scale resolution ****. The simultaneous measurement of temporal profile and beam slice energy spread after the FEL interaction is also shown to reveal the time-dependent x-ray radiation profile *****.
* Z. Huang et al., PRSTAB 13, 092801.
** D. Xiang, Y. Ding, PRSTAB 13, 094001.
*** G. Andonian et al., PRSTAB 14, 072802.
**** D. Xiang et al., PRSTAB 14, 112801.
***** Y. Ding et al., FEL11.
slides icon Slides WEXB01 [6.873 MB]  
TUEPPB015 Generation of Narrow-Band Coherent Tunable Terahertz Radiation using a Laser-Modulated Electron Beam 1146
  • M.P. Dunning, C. Hast, E. Hemsing, R.K. Jobe, D.J. McCormick, J. Nelson, T.O. Raubenheimer, K. Soong, Z.M. Szalata, D.R. Walz, S.P. Weathersby, D. Xiang
    SLAC, Menlo Park, California, USA
  Funding: Work supported by US DOE contract DE-AC02-76SF00515.
The technical layout and initial results of an experiment to generate narrow-band, coherent, tunable terahertz (THz) radiation through the down-conversion of the frequency of optical lasers using a laser-modulated electron beam are described. In this experiment a 120 MeV electron beam is first energy modulated by two lasers with different wavelengths. After passing through a dispersive section, the energy modulation is converted into a density modulation at THz frequencies. This density-modulated beam will be used to generate narrow-band THz radiation using a coherent transition radiator inserted into the beam path. The central frequency of the THz radiation can be tuned by varying the wavelength of one of the two lasers or the energy chirp of the electron beam. The experiment is being performed at the NLCTA at SLAC, and will utilize the existing Echo-7 beamline, where echo-enabled harmonic generation (EEHG) was recently demonstrated.