A high-resolution, low-latency, bunch-by-bunch feedback system for nano-beam stabilization
Abstract
We report the design, operation and performance of a high-resolution, low-latency, bunch-by-bunch feedback system for nano-beam stabilisation. The system employs novel, ultra-low quality-factor cavity beam position monitors (BPMs), a two-stage analogue signal down-mixing system, and a digital signal processing and feedback board incorporating an FPGA. The FPGA firmware allows for the real-time integration of up to fifteen samples of the BPM waveforms within a measured latency of 232 ns. We show that this real-time sample integration improves significantly the beam position resolution and, consequently, the feedback performance. The best demonstrated real-time beam position resolution was 19 nm, which, as far as we are aware, is the best real-time resolution achieved in any operating BPM system. The feedback was operated in two complementary modes to stabilise the vertical position of the ultra-small beam produced at the focal point of the ATF2 beamline at KEK. In single-BPM feedback mode, beam stabilisation to 505 nm was demonstrated. In two-BPM feedback mode, beam stabilisation to 414 nm was achieved.
Cite
@article{arxiv.2201.01531,
title = {A high-resolution, low-latency, bunch-by-bunch feedback system for nano-beam stabilization},
author = {D. R. Bett and N. Blaskovic Kraljevic and T. Bromwich and P. N. Burrows and G. B. Christian and C. Perry and R. Ramjiawan},
journal= {arXiv preprint arXiv:2201.01531},
year = {2022}
}