The SSRL injector beam position monitoring systems

The authors describe the software and processing electronics of the systems used to measure electron beam trajectories for the new Stanford Synchrotron Radiation Laboratory (SSRL) injector and for the Stanford Positron Electron Accelerator Ring (SPEAR). The focus is on the use of the electron beam position monitors (BPMs) to measure electron trajectories in the injector transport lines and the booster ring. There are three different BPM systems in the injector. One system consists of a set of five BPMs located on the injection transport line from the linac to the booster. There is a second system of six BPMs located on the ejection transport line. Finally, there is an array of 40 BPMs installed on the main booster ring itself. The injector beam position monitor systems have successfully been used to measure electron orbits and to diagnose configuration problems. The booster BPM system has proved capable of measuring orbits at intervals of 2 milliseconds during the ramp every two seconds. >