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We report some preliminary results of the Smith-Purcell radiation produced by the interaction of the 28.5 GeV electron beam with a ruled grating at the Stanford Linear Accelerator Center (SLAC). The objects of the experiment were to investigate the longitudinal (temporal) profile of the beam and to confirm that the radiated power was in agreement with the predictions of our surface current theory of the emission. The results are compared with those from earlier, lower, electron energy experiments and preliminary analysis indicates that our theoretical approach is valid over more than a four order range of electron energy from ~2 MeV to ~30 GeV.

We report on measurements of picosecond bunch lengths and the energy-z correlation of the bunch with a high energy electron test beam to the A-line and end station A (ESA) facilities at SLAC. The bunch length and the energy-Z correlation of the bunch are measured at the end of the linac using a synchrotron light monitor diagnostic at a high dispersion point in the A-line and a transverse RF deflecting cavity at the end of the linac. Measurements of the bunch length in ESA were made using high frequency diodes (up to 100 GHz) and pyroelectric detectors at a ceramic gap in the beamline. Modelling of the beam's longitudinal phase space through the linac and A-line to ESA is done using the 2-dimensional tracking program LiTrack, and LiTrack simulation results are compared with data. High frequency diode and pyroelectric detectors are planned to be used as part of a bunch length feedback system for the LCLS EEL at SLAC. The LCLS also plans precise bunch length and energy-Z correlation measurements using transverse RF deflecting cavities.