THE COUPLING IMPEDANCE OF THE RHIC INJECTION KICKER SYSTEM.

In this paper, results from impedance measurements on the RHIC injection kickers are reported. The kicker is configured as a “C” cross section magnet with interleaved ferrite and high-permittivity dielectric sections to achieve a travelling wave structure. The impedance was measured using the wire method in which a resistive match provides a smooth transition from the network analyzer to the reference line in the set-up. Accurate results are obtained by interpreting the forward scattering coefficient via the log-formula. The four kickers with their ceramic beam tubes contribute a Z/n=0.22 Ω/ring in the interesting frequency range from 0.1 to 1 GHz, and less above. At frequencies above ∼ 100 MHz, the impedance is ferrite dominated and not affected by the kicker terminations. Below 100 MHz, the Blumlein pulser with the ∼75 m feeding cables is visible in the impedance but makes no significant contribution to the results. The measurements show that the kicker coupling impedance is tolerable without the need f...