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- G.A. Naylor
ESRF, European Synchrotron Radiation Facility, Grenoble, France
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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.
- 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.
- 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.
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