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Naylor, G.A.

Paper Title Page
CT07 Fast DSP Using FPGAs and DSOs for Machine Diagnostics 71
 
  • G.A. Naylor
    ESRF, European Synchrotron Radiation Facility, Grenoble, France
 
  Digital signal processing using digital signal processors is now a mature field for machine diagnostics, giving significant benefits, in particular when used to analyze BPM signals for tune measurement and fast feedback systems. We discuss here digital signal processing using Field Programmable Gate arrays (FPGAs) with large gate counts and intelligent oscilloscopes. These offer great potential for the analysis of very fast signals to maximize the information extracted from high bandwidth sensors.
  1. FPGAs allow data to be filtered numerically and treated at the speed of data collection of A/D converters in the 100 MHz range. Parallel, fast and continuous treatment of BPM and FCT signals is possible. Examples are given of injection efficiency, turn by turn injection efficiency, turn by turn beam position, amplitude and phase calculation with averaging over each turn or many turns.
  2. Modern oscilloscopes include much computational power. In-built DSPs can perform correlations on the traces allowing the application of FIR filters. Some oscilloscopes incorporate a PC and allow on-board manipulation of the data using MATLAB. An example is given using an FIR applied to a 5 GHz oscilloscope to extend its time response to measure electron bunch lengths less than 100 ps with 1 ps resolution.
 
PT01 Beam Position And Phase Measurements Using A FPGA For The Processing Of The Pick-Ups Signals 169
 
  • G.A. Naylor, E. Plouviez, G.F. Penacoba
    ESRF, European Synchrotron Radiation Facility, Grenoble, France
 
  We have implemented the signal processing needed to derive the transverse beam position and the beam phase from the signals of a four electrodes BPM block on a FPGA (field programmable gate array). The high processing rate of a FPGA allows taking the full benefit of the high data acquisition rate of the most recent ADC circuits. In addition, it is possible to implement on a FPGA a processing algorithm exactly tailored to the measurement of the beam parameters. The efficiency of the signal processing has also been improved by a careful choice of the frequency of the sampling clock and of the RF front-end local oscillator, which are derived from the storage ring RF frequency. This paper describes the BPM, the RF front-end electronics and the FPGA algorithm. It presents some of the application of this BPM at ESRF and gives measurement results.