Performance estimation of vacuum system components including crotch and absorber

A vacuum system of the SPring-8 (Super Photon Ring-8 GeV) storage ring has been designed so as to maintain the beam-on operating pressure of 1 nTorr or less. Special emphasis is placed on the vacuum system components, including absorbers and chamber mounts. The absorbers are designed to efficiently trap various particles from the absorbers, to shut off synchrotron radiation, and to reduce their RF impedances. The chamber mounts are designed to ensure the displacement and deformation of the chamber within the accuracy of 0.05 mm or less, even after each bake cycle. The design results of the absorbers and the chamber mounting systems are described. Calculated and experimental results are briefly discussed.<>