Speaker
Description
Traditional longitudinal bunch‑by‑bunch feedback systems use analog mixers to down‑convert GHz‑range RF signals to baseband, where the mixer output is approximately proportional to the bunch charge and the deviation from the nominal arrival time. We present an alternative approach that determines the beam arrival time through time‑domain processing of directly sampled BPM signals on an RFSoC. We previously demonstrated this method by processing a subset of real‑time ADC data in software on the RFSoC’s internal CPU for slow (Hz‑scale) filling‑pattern measurements and feedback. The new implementation instead processes the full ADC stream continuously in the programmable logic (PL) with low latency. A modified algorithm, optimized for PL, enables continuous arrival‑time measurements for every bunch, as required for low‑latency bunch‑by‑bunch feedback. Using suitable time‑domain techniques, even large arrival‑time variations can be measured with higher linearity, without a phase‑tuned local oscillator. Traditional systems cannot achieve this, as analog down‑conversion becomes increasingly nonlinear — and even non‑monotonic — for larger timing deviations, a common limitation in booster synchrotrons. We present measurements from the SLS 2.0 storage ring, demonstrating the feasibility of the implementation using an RFSoC with eight interleaved 4‑GS/s ADCs, achieving a 32‑GS/s effective sampling rate.
| I have read and accept the Privacy Policy Statement | Yes |
|---|