Estimation of broad band impedance of the SPring-8 storage ring

The broad band impedance of the vacuum chamber of the SPring-8 storage ring was estimated with several analytical equations and the numerical simulation with MAFIA T2. The estimated value of the total impedance is a few 10/sup -1/ /spl Omega/. The vacuum chamber consists of the beam chamber and the slot-isolated antechamber. The effect of the obstacles in the slot is estimated numerically, which shows that the designed shape is effective to reduce the impedance of them.<>