Success of timing in FACET : Electro-Optic Sampling Yunfeng Xi, Aihua Deng, Oliver Karger, Alexander Knetsch, Grace Manahan, Bernhard Hidding, James Rosenzweig Sep. 15, 2015 La Biodola, Isola d’Elba

E210 Collaboration

Timing: A key to E210 success 150 fs 5x10 16 cm um 500 fs 5x10 17 cm um 150 fs B. Hidding et al., PhysRevLett

Electro-Optic Sampling (EOS) Intense electric field of e-beam induces a birefringence which rotates probe’s polarization. e bunch Phase delay S. Casalbuoni et al., Phys. Rev. ST Accel. Beams 11, (2008)

Electro-Optic Sampling (EOS) The position of signal, where laser crosses with crystal indicates the time of arrival of ebeam. The width of signal is related to longitudinal profile of ebeam. A. L. Cavalieri et al., PhysRevLett (2005)

FACET experiment area

EOS_Lo Probe line monitor IPOTR 1 E224_Trans E210_Focus EOS_Hi IPOTR 2 upstream EOS downstream EOS and injection point cube 1 cube 2 cube 3cube 4cube 5 setup at FACET FACET experiment area main injection laser sampled probe laser

Upstream EOS layout CCD_HI CCD_LO e-beam EO crystal Delay stage Plasma Main Laser Pulse EOS Probe Pulse 45° Vertical polarization Analyze r 1cm 50µm x 1cm x 1cm (110) cut, GaP 500µm x 1cm x 1cm, (110) cut, ZnTe YAG e-

EOS signals Shadow signal

Laser timing scan IR laser ebeam

Arrival timing jitter Clocked FACET laser timing jitter for the first time

Phase ramp effect Phase ramp scan from 47° to 52°. 50 shots are taken on each step. Timing delay is plotted relative to first step of each scan.

DS-1 for EOS DS-2 for TH TH injection point MgF2 window New E210 interaction region design

Summary FACET laser and e-beam have been synchronized at ~100 fs. We calibrated effect of phase ramp on FACET laser relative timing to ebeam. We are designing new EOS layout based on new injection chamber.