Discrete Element Transmission Line Beam Spreader Kickers for LCLS-II

The LCLS-II project requires a beam spreader to distribute the 929 kHz electron beam between two undulators and a dump. Three kicker sections and a septum are required to divert beam for each undulator. When the kickers are not pulsed, beam proceeds to the dump. Each kicker magnet is approximately one meter in length and composed of multiple sections. Each section consists of a ferrite and a capacitor to form a lumped element transmission line. The output magnetic field is a <; 250 ns base-to-base pulse with an amplitude of 4 mT. This paper presents the unique challenges of designing a transmission line kicker and driver with >500 kHz pulse rate. Provided experimental data illustrates pulse-to-pulse repeatability of approximately 100 ppm, transverse field quality, and field-settling time. Additional discussion includes thermal considerations and circuit protection. Adaptation of the kicker system for a low field long flattop pulse is also considered.