Design and offline tests of a resonant stripline cavity kicker for longitudinal feedback in the HEPS Booster ☆

Resonant stripline cavity kicker was first proposed by Spring-8 as a highly efficient longitudinal feedback kicker, since the shunt impedance per length of this type of kicker is higher than that of the widely-used waveguide-loaded cavity kicker. This paper presents the design of a resonant stripline cavity kicker for the HEPS Booster with a smaller beampipe compared to Spring-8. Based on the time domain measurements and the particle-in-cell simulation results, the designed kicker with a length of 402 mm is expected to achieve a peak shunt impedance of 4140 Omega and a minimum shunt impedance of 2700 Omega within the bandwidth from 1.5 GHz to 1.75 GHz, demonstrating itself a higher efficiency over the waveguide-loaded cavity kicker. Besides, the analyzed coupling beam impedance of this kicker indicates it not a source of beam instability. All these results suggest the resonant stripline cavity kicker an ideal choice to simultaneously fulfill feedback requirements and save installation space even on a smaller size scale.