The SDDS 200k file above is binary and represents 200k macro-particles tracked through Parmela to 150 MeV and then through Elegant
to 14.345 GeV at the LCLS undulator entrance. The linac tracking includes a 1D CSR model for all bends and nearby drifts, longitudinal geometric structure wakefields, and
2nd-order optics, etc. The point where the particles are dumped has been matched to betaX=20.15 m, alphaX=-1.144, betaY=14.947 m,
alphaY=0.8180, which assumes the undulator starts with an X-focusing full-length quadrupole magnet. The bunch charge is 1 nC, the rms bunch length is 21
microns, and the rms energy spread (beam core) is <1E-4. The sliced emittances are ~1 micron, with an x-projected emittance of ~2.8
microns due to CSR effects.
The second file above (Sliced Bunch) is derived from the same 200k particles as the SDDS file, but the bunch has been sliced 125
times (~once per slippage length). The results are 125 ascii rows with centroid, and rms values for each slice. This is the file
format used in the past for Genesis 1.3 input (see PAC01, S, Reiche, et al.).