INSTALLATION OF A 14 MM VACUUM CHAMBER FOR AN UNDULATOR IN THE 1.3 GEV STORAGE-RING AT SYNCHROTRON-RADIATION-RESEARCH-CENTER

An aluminum alloy vacuum chamber, 4 m in length, for an undulator was installed in the 1.3 GeV electron storage ring of the Synchrotron Radi ation Research Center in the spring of 1996. The inner cross section o f this vacuum chamber is an elliptical shape, 10 mm in height and 80 m m in width. A beam life time of 7 h at 200 mA beam current was quickly achieved after beam cleaning on the new chamber walls. The impact of this new vacuum chamber, before and after the installation, to the sto rage ring was compared. The injection rate was reduced. The stronger b eam loss during the injection was measured. The effects of a small ver tical aperture and the effective pumping to the electron beam lifetime are reported. The planning in upgrading the storage ring vacuum syste m is also described. (C) 1997 American Vacuum Society.