The CEBAF accelerator at Jefferson Lab is currently using an analog beam current monitoring (BCM) system for its machine protection system (MPS), which has a loss accuracy of 2 micro-amps. Recent burn-through simulations predict catastrophic beam line co mponent failures below 1 micro-amp of loss, resulting in a blind spot for the MPS. Revised MPS requirements target an ultimate beam loss accuracy of 250 nA. A new beam current monitoring system has been developed which utilizes modern digital receiver t echnology and digital signal processing concepts. The receiver employs a direct-digital down converter integrated circuit, mated with a Jefferson Lab digital signal processor VME card. Adaptive filtering is used to take advantage of current-dependent bu rn-through rates. Benefits of such a system include elimination of DC offsets, generic algorithm development, extensive filter options, and interfaces to UNIX-based control systems.

This work was supported by the U.S. DOE Contract No DE-AC05-84ER40150.

Authors: J. Musson, H. Dong, R. Flood, C. Hovater, J. Hereford

Abstract submitted to PAC 2001, Chicago, IL, June 18-24, 2001

Updated July 27, 2001

maintained by the Publications Manager