Publications by Douglas Bett


Applications of stripline and cavity beam position monitors in low-latency, high-precision, intra-train feedback systems

IBIC 2013: Proceedings of the 2nd International Beam Instrumentation Conference (2013) 630-633

MR Davis, DR Bett, PN Burrows, N Blaskovic Kraljevic, GB Christian, YI Kim, C Perry

Copyright © 2013 by JACoW. Two low-latency, sub-micron, beam position monitoring (BPM) systems have been developed and tested with beam at the KEK Accelerator Test Facility (ATF2). One system (upstream), based on stripline BPMs, uses fast analogue front-end signal processing and has demonstrated a position resolution as low as 400 nm for beam intensities of 1 nC, with single-pass beam. The other (IP) system, based on low-Q cavity BPMs and utilising custom signal processing electronics designed for low latency, provides a single pass resolution of approximately 100 nm. The BPM position data are digitised by fast ADCs on a custom FPGA-based feedback controller and used in three modes: 1) the upstream BPM data are used to drive a pair of local kickers nominally orthogonal in phase in closed-loop feedback mode; 2) the upstream BPM data are used to drive a downstream kicker in the ATF2 final focus region in feedforward mode; 3) the IP cavity BPM data are used to drive a local downstream kicker in the ATF2 final focus region in closed-loop feedback mode. In each case the beam jitter is measured downstream of the final focus system with the IP cavity BPMs. The relative performance of these systems is compared.


Show full publication list