Dual Energies in the LCLS Copper Linac

For LCLS-II two undulators were installed at SLAC, one for soft and one for hard x-rays. Before the superconducting linac gets turned on the copper linac is providing beams at 120 Hz to these two beam destinations. The 120 Hz can be split in many different ratios between soft and hard via a pulsed magnet. To get an optimized beam for the quite different photon energies the pulsed linac components like modulators and RF can provide many different beam parameters, mainly energies and bunch lengths for the two undulator lines. How this was implemented with timing setups of triggers and finally after the split the necessary matching of the transverse phase space will be discussed. PULSED BEAM MANIPULATION The two undulators have their optimal intensity performance around 10-12 GeV for the Hard X-Ray line (HXR), and 4-6 GeV for the Soft X-Ray line (SXR). Since the copper linac is a pulsed at 120 Hz, each pulse can have different trigger assignments and the RF can have different amplitudes and phases. This enables beams with different energies like in the past [1], different bunch lengths, and different charges at a few different rate ratios, for example one beam can have 0, 1, 10, 30, or 60 Hz, while the other beam gets the rest of the 120 Hz.