Development of a 750-mm-long stripline kicker for HEPS

Purpose The superfast kickers are required for the HEPS storage ring on-axis injection system due to its very small dynamic aperture. A 750-mm-long stripline pair type of kicker prototype was researched and developed to demonstrate achieved performance of bandwidth, impedance, kicker strength, field uniformity and beam power loss. Methods The cross sections of the kicker main body and the end of taper part are optimized for a good impedance matching and field uniformity. 3D simulation further optimizes the taper part to minimize the beam power loss and maintain a lower reflection. The high-voltage feedthrough is also designed and optimized by 3D CST. RF and high-voltage measurements are taken to verify the design of kicker assembly. Results The testing transmission odd-mode impedance is 50 ± 0.5 Ω, the even-mode impedance is 60 ± 0.5 Ω, and return loss is less than − 13 dB. The peak voltage and the rise time of pulse width inserting kicker assembly just decrease 3% of 20 kV and slow down 80 ps, respectively. Conclusions RF testing results agree well with the simulation ones, which meet the design specification. The kicker assembly works well at ± 20 kV pulse.