APS storage ring vacuum system development

The Advanced Photon Source synchrotron radiation facility, under construction at the Argonne National Laboratory, incorporates a large ring for the storage of 7-GeV positrons for the generation of photon beams for the facility's materials research program. The storage ring's 1104 m circumference is divided into 40 sectors which contain vacuum, beam transport, control, RF, and insertion device systems. The vacuum system will operate at a pressure of 1 nTorr and is fabricated from aluminum. The system includes distributed NeG pumping, photon absorbers with lumped pumping, beam positron monitors, vacuum diagnostics, and valving. An overview of the vacuum system design and details of selected development program results are presented. >