Development of a BPM lock-in diagnostic system

A system has been developed for the acquisition and analysis of high rate, time coherent BPM data across the Jefferson Lab´s Continuous Electron Beam Accelerator Facility (CEBAF). This system will allow the acquisition of Beam Position Monitor (BPM) position and intensity information at a rate in excess 7 KHz for approximately 200 BPMs in a time synchronous manner. By inducing minute sinusoidal transverse beam motion in the CEBAF injector, with known phase relative to the synchronized BPM acquisition, it is possible to derive several types of useful information. Analysis of the BPM intensity data, which is proportional to beam current, by beating the signal with an in-phase sinusoidal representation of the transverse kick can localize beam scraping to a particular BPM. Similarly, real-time optics information may be deduced with an analysis of BPM position data. This paper will detail the frequency lock-in technique applied and present status.