Design, testing and performance results of a high-resolution, broad-band, low-latency stripline beam position monitor system
6th International Particle Accelerator Conference, IPAC 2015 (2015) 1136-1138
Abstract:
A high-resolution, low-latency beam position monitor (BPM) system has been developed for use in particle accelerators and beamlines that operate with trains of particle bunches with bunch separations as low as several tens of nanoseconds, such as future linear electronpositron colliders and free-electron lasers. The system was tested with electron beams in the extraction line of the Accelerator Test Facility at the High Energy Accelerator Research Organization (KEK) in Japan. The fast analogue front-end signal processor is based on a single-stage RF down-mixer. The processor latency is 15.6 +-0.1 ns. A position resolution below 300 nm has been demonstrated for beam intensities of around 1 nC, with single-pass beam.Progress towards electron-beam feedback at the nanometre level at the Accelerator Test Facility (ATF2) at KEK
6th International Particle Accelerator Conference, IPAC 2015 (2015) 1133-1135
Abstract:
Ultra-low latency beam-based digital feedbacks have been developed by the Feedback On Nanosecond Timescales (FONT) Group and tested at the Accelerator Test Facility (ATF2) at KEK in a programme aimed at beam stabilisation at the nanometre level at the ATF2 final focus. Three prototypes were tested: 1) A feedback system based on high-resolution stripline BPMs was used to stabilise the beam orbit in the beamline region c. 50m upstream of the final focus. 2) Information from this system was used in a feed-forward mode to stabilise the beam locally at the final focus. 3) A final-focus local feedback system utilising cavity BPMs was deployed. In all three cases the degree of beam stabilisation was observed in high-precision cavity BPMs at the ATF2 interaction point. Latest results are reported on stabilising the beam position to below 100 nanometres.Status of ATF2 IP-BPM project
6th International Particle Accelerator Conference, IPAC 2015 (2015) 777-780
Abstract:
The efforts during the second half of 2014 towards nanometric beam position measurement and stabilization at the Interaction Point (IP) section of the Accelerator Test Facility (ATF) at KEK are presented. Recent improvements to the beam position monitor (BPM) data analysis and processing electronics, as well as the installation of a new set of C-Band BPMs, are reviewed.A sub-micron resolution, wide-band, stripline bpm system for driving bunch-by-bunch feed-back and feed-forward systems at ATF
IPAC 2014: Proceedings of the 5th International Particle Accelerator Conference (2014) 1358-1360
Abstract:
A low-latency, sub-micron resolution stripline beam position monitoring (BPM) system has been developed and tested with beam at the KEK Accelerator Test Facility (ATF2), where it has been used as part of a beam stabilisation system. The fast analogue front-end signal processor is based on a single-stage RF down-mixer and a position resolution below 400 nm has been demonstrated for beam intensities of 1 nC, with single-pass beam. The BPM position data are digitised by fast ADCs on an FPGA-based digital feedback controller, which is used to drive either a pair of kickers local to the BPMs and nominally orthogonal in phase, in closed-loop feedback mode, or a downstream kicker in the ATF2 final focus region, in feedforward mode. The beam jitter is measured downstream of the final focus system with high resolution, low-Q, cavity BPMs, and the relative performance of both systems in stabilising the beam is compared.Development of a low-latency, high-precision, intra-train beam feedback system based on cavity beam position monitors
IPAC 2014: Proceedings of the 5th International Particle Accelerator Conference (2014) 2783-2785