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TY - CONF AU - Lumpkin, A.H. AU - Eddy, N. AU - Edstrom, D.R. AU - Ruan, J. AU - Thurman-Keup, R.M. ED - Schaa, Volker RW ED - Jansson, Andreas ED - Shea, Thomas ED - Olander, Johan TI - Observations of Long-Range and Short-Range Wakefield Effects on Electron-Beam Dynamics in TESLA-type Superconducting RF Cavities J2 - Proc. of IBIC2019, Malmö, Sweden, 08-12 September 2019 CY - Malmö, Sweden T2 - International Beam Instrumentation Conferenc T3 - 8 LA - english AB - The Fermilab Accelerator Science and Technology (FAST) facility has a unique configuration of a photocathode rf gun beam injecting two TESLA-type single cavities (CC1 and CC2) in series prior to the cryomodule. Beam propagation off axis in these cavities can result in both long-range and short-range transverse wakefields which can lead to emittance dilution within the macropulses and micropulses, respectively. Two configurations of a Hamamatsu C5680 streak camera viewing a downstream OTR screen were utilized to track centroid shifts during the macropulse (framing mode) for the long-range case and during the micropulse for the short-range case (~10-micron spatial resolution and 2-ps temporal resolution). Steering off axis before CC1, resulted in a 100-kHz bunch centroid oscillation within the macropulse that was detected by the downstream rf BPMs and the streak camera*. At 500 pC/b, 50b, and 4-mrad off-axis vertical steering into CC2, we observed an ~ 100-micron head-tail centroid shift in the streak camera image y(t) profiles which we attributed to a short-range wakefield effect. Additional results for kick-angle compensations and model results will be presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 428 EP - 431 KW - cavity KW - HOM KW - wakefield KW - FEL KW - detector DA - 2019/11 PY - 2019 SN - 2673-5350 SN - 978-3-95450-204-2 DO - doi:10.18429/JACoW-IBIC2019-TUPP041 UR - http://jacow.org/ibic2019/papers/tupp041.pdf ER -