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    User name brads

    Log entry time 10:41:06 on October 28, 2009

    Entry number 296882

    This entry is a followup to: 296869

    keyword=Fixed noisy MPS signal to orig Moller DAQ

    Sasha's analysis suggested that the noisy MPS signal was interfering with the orig Moller DAQ. (Too much data was being discarded, impacting statistics.)

    We elected to use the cleaned-up signal I made for the FADC DAQ (Halog 296017 for his DAQ as well.

    The MPS signal from the counting house on cable 002 is now run into a GDG in the FADC NIM bin. The GDG triggers is set to generate a clean 500us window (same length as the original). It's then fanned out to the old and new systems. Net impact on the old system is that the MPS arrives ~30ns later than it used to. (Should be too small a difference to matter -- the relevant timescale for the helicity signals is microseconds).

    Note that the MPS signal still lags the HEL and QRT signals by about 1.5 usec as was noted on the 21st.

    Figure 1: (Before) Yellow is noisy MPS, blue and pink are QRT and HEL.
    Figure 2: (After) Yellow is noisy MPS, blue and pink are QRT and HEL.

    A copy of this log entry has been emailed to: gen, glamazdi, brads

    Figure 1

    Figure 2