Advanced Photon Source low-energy undulator test line bunch compressor beam position monitor system

This paper describes the design and development of a new beam position monitor (BPM) system designed specifically for the Advanced Photon Source Low-Energy Undulator Test Line (LEUTL) bunch compressor. The photocathode gun used for LEUTL presents new challenges for BPM systems. These challenges warranted the development of a new BPM system with a novel surface acoustic wave filter front-end and low-cost monopulse receiver. The system is designed to simultaneously measure single-shot position in both x and y planes using amplitude-to-phase signal processing topology. A logarithmic amplifier channel measures the beam intensity, which can be used as an indicator of shot-to-shot charge fluctuations. The latest experimental results using these BPMs are presented.