Measurements of wake-induced electron beam deflection in a dechirper at the Linac Coherent Light Source

Abstract

The RadiaBeam/SLAC dechirper, a structure consisting of pairs of flat, metallic, corrugated plates, %a corrugated structure in flat geometry, has been installed just upstream of the undulators in the Linac Coherent Light Source (LCLS). As a dechirper, with the beam passing between the plates on axis, longitudinal wakefields are induced that can remove unwanted energy chirp in the beam. However, with the beam passing off axis, strong transverse wakes are also induced. This mode of operation has already been used for the production of intense, multi-color photon beams using the Fresh-Slice technique, and is being used to develop a diagnostic for attosecond bunch length measurements. Here we measure, as function of offset, the strength of the transverse wakefields that are excited between the two plates, and also for the case of the beam passing near to a single plate. We compare with analytical formulas from the literature, and find good agreement. This report presents the first systematic measurements of the transverse wake strength in a dechirper, one that has been excited by a bunch with the short pulse duration and high energy found in an X-ray free electron laser.

arXiv comment8 pages, double column, 6 figures

References in corpus (3)

• SASE FEL with energy-chirped electron beam and its application for generation of attosecond pulses
• Analytical Formulas for Short Bunch Wakes in a Flat Dechirper
• Time-resolved Measurement of Quadrupole Wakefields in Corrugated Structures

Cited by in corpus (4)

• Analytical treatment of the wakefields driven by transversely shaped beams in a planar slow-wave structure
• Generation of coherent two-color pulses at the two adjacent harmonics in a seeded free-electron laser
• Simulation studies for dielectric wakefield programme at CLARA facility
• Wake Measurements of a Dechirper Jaw with Non-Zero Tilt Angle