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LCLSII 5keV FEL SASE simulations. Y. Ding (SLAC) LCLSII physics meeting 11/6/2013. Ideal flat beam check. 4 GeV , 1kA, 0.4 µ m emittance , 500keV energy spread; Undulator period 2.6cm, K = 0.585 (aw=0.414 ); Each section 3.38m (N=130), break 1.17m (N=45).
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LCLSII 5keV FEL SASE simulations Y. Ding (SLAC) LCLSII physics meeting 11/6/2013
Ideal flat beam check • 4 GeV, 1kA, 0.4µm emittance, 500keV energy spread; • Undulator period 2.6cm, K = 0.585 (aw=0.414); • Each section 3.38m (N=130), break 1.17m (N=45). • Total undulatorbeamline including breaks and U16( it is a drift in setup) is ~150m. • FEL 5keV (2.486 Angstrom) • Checked emittance, current and beta function with Genesis simulations using a flat beam.
Ideal flat beam: gain curve vsemittance Gain vs. current (beta function 15m, 0.3µm, 500keV energy spread). Gain vs. emittance (beta function 15m, 1kA, 500keV energy spread). 0.35µm 0.3µm 1kA 800A 0.4µm
S2E beam from Paul 4GeV, 100pC: ~1kA, 500keV energy spread, core slice emittance~0.3µm. head 0.3µm slice emittance
Match and center the core part t-x t-xp head
Match and center the Core part head Average beta 20m Total pulse energy ~ 18µJ, ~ 35 fs (half of e-beam )
Summary: 5keV, SASE • Resistive wall wake field from undulator chamber is checked, and negligible at this beam condition. • With the present S2Ebeam, it barely works at 5keV and the core 0.3um emittance helps. • CSR limits higher currents. This might be further optimized. • LSC and mircobunching not included in this S2E beam.