Advanced Photon Source booster synchrotron beam position monitor upgrade and applications

The Advanced Photon Source operates in top-up mode, which adds charge to the storage ring every two minutes to maintain the current at 102±1.0 mA. This requires the booster synchrotron to operate efficiently and reliably. The booster BPM system was upgraded to overcome a severe performance limitation due to operation of the receiver at the low end of its input power range. The upgrade provided a 25-dB improvement in overall system gain. This improved dynamic range and resolution, and reduced other systematic errors. The booster BPMs have been used in studies including measurements of ring circumference, synchrotron and betatron tune, and orbit correction. Software feedback corrections of the energy and RF phase errors at injection have been implemented for routine operations using the BPM beam history/DSP-based synchrotron tune measurement. Transverse injection feedback is presently being commissioned. The latest experimental results using the upgraded BPMs will be presented.