The vacuum system for the Daresbury synchrotron radiation source

At the Daresbury Laboratory a new facility is being built for research using synchrotron radiation. The source will be a 2 GeV 1 A electron storage ring of about 30 m dia, which can accommodate up to 12 beam lines radiating tangentially from it. The ultra-high vacuum in the storage ring will be maintained by ion and titanium sublimation pumps in the straight sections and distributed ion pumps in the bending magnet chambers. For adequate beam lifetime and for tolerable bremsstrahlung down each beam line a working pressure of 10-9 torr for CO is required. To reach this pressure a number of measures will be necessary to obtain low enough desorption rates from photo-electrons produced by up to 255 kW of synchrotron radiation. (author)