Libera Spark ERXR

Libera Spark (version ERXR) is a compact electron beam position processor that offers high-precision position measurement. It is optimized to work with button and stripline pickups. The digital signal processing supports detailed adjustment of the processing window and position measurement in various regimes and bandwidths. Optionally, it supports the pilot tone processing, too. The data available to the user ranges from bunch-to-bunch, turn-by-turn to slow data stream. The instrument is typically used in booster or storage rings.

Product Description


  • Best price/performance ratio
  • Compact and robust design
  • Power over Ethernet
  • No maintenance required
  • Source code available
  • Variety of interfaces (e.g. EPICS, TANGO, HTTP, MATLAB, etc.)

Data Processing:

Input signals are sampled at 100-125 MHz PLL-controlled sampling frequency. Raw ADC data is stored in a buffer and further processed through a time-domain processing block (TDP) and frequency-domain processing block (DDC, I&Q demodulation). Optionally, a special instrument’s version supports additional DDC block for pilot-tone signal.

The turn-by-turn processing blocks can be fine-tuned with processing delay, offset and masking window. Data from first turns and other machine studies is available on-demand using hardware or software trigger.

The Fast and Slow data are both generated from the turn-by-turn data using FIR filters with 2 kHz and 5 Hz bandwidths, respectively. Optionally, the Fast data can be output through a dedicated RJ-45 interface as a real-time data stream.


Libera Spark ERXR Performance
Temperature drift, typical2 μm/°C
Position RMS at turn-by-turn data rate0,3 μm
Position RMS at fast 10 kHz data rate0.04 μm
Position RMS at slow 10 Hz data rate0.02 μm
Position RMS at single bunch< 10 μm
Position RMS at macro pulse/continuous wave/
Libera Spark ERXR
Clear filters
Commissioning results of the new BPM electronics of the ESRF booster synchrotron* (IPAC’15, Richmond, VA, USA)
Spark EL Single Pass BPM (FEL 2015, Daejaon, S. Korea)

For demonstration purposes, Libera Spark can be fully controlled with a Qt Graphical User Interface. It uses a netcat utility that connects to Libera Spark via SCPI set/read commands. Check example figures and tutorial videos.

Libera Spark – ADC

Libera Spark – FFT

Libera Spark – Parameters

Libera Spark – TBTXY


Getting started with GUI

Set up the custom ADC sampling frequency

ADC data readout


Kees Scheidt
Diagnostics Head (ESRF, Grenoble)

On our Booster beam, we collected much data and features, that we could not measure or even detect before.

Engineering Executive
NDA locked

The prototyping and development Instrumentation Technologies has provided for our team has been exceptional.

Libera Spark ERXR is used at the following labs:

  • DIAMOND Light Source (United Kingdom)
  • SACLA – Spring-8 (Japan)
  • Synchrotron Light Research Institute – SLRI (Thailand)
  • The European Synchrotron Radiation Facility – ESRF (France)
  • Argonne National Laboratory – APS (United States)
  • National Institutes of Natural Sciences, Institute of Molecular Science – UVSOR facility (Japan)
  • Cornell University – CHESS (United States)