• J.C. Frisch, R. Akre, F.-J. Decker, Y.T. Ding, D. Dowell, P. Emma, A. Gilevich, G.R. Hays, P. Hering, Z. Huang, R.H. Iverson, R.G. Johnson, C. Limborg-Deprey, H. Loos, E. A. Medvedko, A. Miahnahri, H.-D. Nuhn, J.L. Turner, J.J. Welch, G.R. White, J. Wu
  SLAC, Menlo Park, California
• D.F. Ratner
  Stanford University, Stanford, Califormia

The LCLS accelerator produces a 14GeV beam with a normalized emittance on the order of one micron RMS, and peak current exceeding 10⁰⁰ Amps. The design of the beam measurement system relied heavily on optical transition radiation profile monitors, in conjunction with transverse cavities, and conventional energy spectrometers. It has been found that the high peak currents, and small longitudinal phase space of the beam generate strong coherent optical emission that prevents the use of OTR or other prompt optical diagnostics, requiring the use of wire scanners or fluorescent screen based measurements. We present the results of the beam measurements, measurements of the coherent optical effects, and future plans for diagnostics.

Slides