• G. Andonian
  RadiaBeam, Marina del Rey
• G. Andonian, E. Hemsing, P. Musumeci, J.B. Rosenzweig, S. Tochitsky
  UCLA, Los Angeles, California

For successful operation and beam characterization, fourth generation light sources require the observation of sub-picosecond bunches with femtosecond resolution. In this paper, we report on the design and development of a novel technique to achieve sub-femtosecond temporal resolution of high brightness bunches. The technique involves the coupling of the electron beam to a high power laser in an undulator field, which is optimized to maximize the angular deviation of the bunch. The beam angular components are imaged on a distant screen yielding a sweep across angles in one dimension. The addition of an x-band deflecting cavity downstream of the undulator creates another sweep of the beam, in the perpendicular dimension. The temporal resolution of the bunch is dependent on the seed laser wavelength and the spatial resolution of the screen. Initial calculations show that for a CO₂ laser (T~30fs) and a phosphor screen (~50micron spatial resolution), the longitudinal resolution is approximately l/200 of the laser wavelength, or ~150 attoseconds.