Pulse-to-Pulse Emittance Measurement System

50313-98-I Pulse-to-Pulse Emittance Measurement System--FARTECH, Inc., 3146 Bunche Avenue, San Diego, CA 92122-2247; (619) 455-6607 Dr. Jin-Soo Kim, Principal Investigator Dr. Jin-Soo Kim, Business Official DOE Grant No. DE-FG03-98ER82574 Amount: $75,000 Beam emittance is a critical parameter for accelerator applications including colliders and radiation generation (free-electron lasers). At present there is no existing technique, commercial or otherwise, for non-destructive pulse-to-pulse emittance measurement. Currently, the only working technique for high energy electron beams employs wire-scanners, requiring multiple machine pulses (large beam-time requirement for tune-up) and large capital cost ($100K per scanner for 8 scanners). In addition, these systems are mechanically fragile, necessitating continual maintenance. A cavity-based technique has been conceived permitting measurement of beam quadrupole moments, on a single-pulse, without beam interception, and without moving parts. This project will produce a working design for a pulse-to-pulse emittance measurement system, including beam optics analysis, and designs for the magnetic lattice and the resonant cavity. In Phase II, a prototype cavity will be fabricated, bench-tested, and tested with beam. Phase I will provide analysis of the systematics of the cavity pickup (common-mode, misalignments, electronics), electromagnetic modeling of the cavity and design structure dimensions (cavity & couplers). A conceptual design will be produced including the magnetic lattice and cavity placement on the beamline. This emittance measurement system will be analyzed accounting for magnetic lattice and cavity-derived systematic errors, to determine figures of merit for achievable beam-size, and emittance resolution. Commercial Applications and Other Benefits as described by the awardee: This technique for in-line, non-destructive, pulse-to-pulse, measurement of beam emittance can be applied to all particle accelerators where maintaining beam quality is crucial, from high energy physics accelerators to medical application accelerators. This system can offer superior functionality (pulse-to-pulse resolution) and much lower cost (a factor of ten or more) than the presently available wire scanner systems._