Wake Measurements of a Dechirper Jaw with Non-Zero Tilt Angle

TL;DR

This paper develops a model-independent method to correct unknown tilt in dechirper jaws and validates it through measurements, deriving an explicit formula for transverse wake kicks and confirming excellent agreement with theory.

Contribution

It introduces a new method to remove unknown tilt in dechirper jaws and provides an analytical formula for transverse wake kicks, validated by measurements.

Findings

Measurement and theory agree well on wake kicks.

The method effectively removes unknown tilt during setup.

Analytical formula accurately predicts transverse wake effects.

Abstract

The RadiaBeam/SLAC dechirper at the Linac Coherent Light Source (LCLS) is being used as a fast kicker, by inducing transverse wakefields, to e.g. facilitate Fresh-slice, two-color laser operation. The dechirper jaws are independently adjustable at both ends, and it is difficult to avoid leaving residual (longitudinal) tilt in them during set-up. In this report we develop a model independent method of removing unknown tilt in a jaw. In addition, for a short uniform bunch passing by a single dechirper plate, we derive an explicit analytical formula for the transverse wake kick as function of average plate offset and tilt angle. We perform wake kick measurements for the different dechirper jaws of the RadiaBeam/SLAC dechirper, and find that the agreement between measurement and theory is excellent.