• S.P. Weathersby, E.R. Colby, M.P. Dunning, A. Gilevich, C. Hast, R.K. Jobe, D.J. McCormick, J. Nelson, T.O. Raubenheimer, K. Soong, G.V. Stupakov, Z.M. Szalata, D.R. Walz, M. Woodley, D. Xiang
  SLAC, Menlo Park, California
• P.L. Pernet
  EPFL, Lausanne

ECHO-7 is a proof-of-principle echo-enabled harmonic generation FEL experiment in the Next Linear Collider Test Accelerator (NLCTA) at SLAC. The experiment aims to generate coherent radiation at 318 nm and 227 nm, which are the 5th and 7th harmonic of the infrared seed laser. In this paper we present the experimental results from the commissioning run of the completed experimental setup which started in April 2010.

Slides

• F.-J. Decker, R. Akre, A. Brachmann, Y.T. Ding, D. Dowell, P. Emma, A.S. Fisher, J.C. Frisch, A. Gilevich, P. Hering, Z. Huang, R.H. Iverson, H. Loos, M. Messerschmidt, H.-D. Nuhn, D.F. Ratner, W.F. Schlotter, T.J. Smith, J.L. Turner, J.J. Welch, W.E. White, J. Wu
  SLAC, Menlo Park, California

The Linac Coherent Light Source at SLAC is a hard X-ray FEL which was designed for single electron bunch operation. Although most user experiments are not interested in multiple bunches from an S-band linac due to their short (ns) separation, there are some advantages with multi-bunch operation. Starting with two bunches where the delayed light of one bunch is used to seed the light of a second bunch, to many more bunches to increase the likelihood of rare target collisions, multi-bunch operation would open more options for the LCLS. In the past the SLAC Linac has operated with a few dedicated bunches for the SLC (Stanford Linear Collider), and up to 1400 bunches for some fixed target experiments, so a few bunches for the LCLS seems possible even with the original single bunch design. This paper will describe how the current RF implementation supports multi-bunch operation. Initial experimental tests with two bunches are presented.