Demonstration of Energy-Chirp Control in Relativistic Electron Bunches at LCLS Using a Corrugated Structure

Start2017/04/07(Fri) 1:30 PM
End2017/04/07(Fri) 3:00 PM
Venue2nd buld, Meeting room, Large
SpeakerKarl Bane (SLAC)
ContactK.Ohmi (PHS 4413)


In a linac-based X-ray FEL, the beam, after the final bunch compressor, is normally left with an energy chirp, one that typically needs to be removed before the beam enters the undulator for lasing. The corrugated pipe as a beam dechirper was developed as a passive and simple solution to this task. In 2015 a flat version of the dechirper--consisting of two corrugated plates--was built and installed in the Linac Coherent Light Source (LCLS) at SLAC. During its commissioning it was soon realized that passing the beam close to a single plate induces a fast, longitudinally correlated transverse kick that facilitates? self-seeding,fresh slice, and two color modes of operation of the FEL. In this talk we present commissioning measurements of this device, including time-resolved measurements of both longitudinal and transverse wakefields, and measurements of the effect on lasing.