SSRF storage ring must use the bellows with RF shield which contain a high frequency shield structure inside. The RF shield structure is called “double finger shield structure” which consists of contact fingers and spring fingers. The key design parameters of an RF shield structure are the contact force between a pair of fingers and the width and length of the slit between adjacent fingers

while the former is decided by the wall beam current and wall electric field

the latter is depedent on HOM. RF shield bellows have experienced a heat test and an impedance test. The test results show that the contact force

slit and impedance of the bellows are suitable for the actual operating conditions on SSRF.