The Operation of SSRF Storage Ring Vacuum System

The storage ring of SSRF began to commissioning at the end of 2007, and have past 2 years so far .Many problems about vacuum system were found and resolved during this period. Residual gas scattering beam lifetime is more than 100 hours, and Touschek beam lifetime is 17hours,the total beam lifetime is about 16hours (200mA/3.5GeV).These indicate that Touschek effect is the main limitation to total beam lifetime but not residual gases. Beam current reached the designed target 200mA/3.5GeV in October 2008,the average pressure of storage ring is 1.52×10-7Pa.After running for several months, the dynamic pressure went down to 6.8×10-8Pa,which is much lower than the designed target.