Cluster Reconstruction in 3 detectors
( FermiLab test beam data taken in May of 2007 , based on May4_run21 )
Updated, September 28,2007

  1. this run "May4_run21" has been already processed by Frank, one can make direct comparison

  2. Use U & V-planes of detector B from a single run have been processed.

  3. Details about geometry/setup
    -strip pitch 635 um
    - both planes B and C are 1 mil boards that have "bad" charge sharing,
    while plane A is a 2 mil board that does better.
    -  May 4 was before good tuning of high voltage,  repeat analysis for a run from May 7 or later

  4. All 3 detectors (A,B,C) were calibrated as discussed here .

  5. Cluster finder algorithm There are 2 parameters:
    seed threshold=70 ADC
    total cluster width of 7 strips centered at the seed strip (3+1+3)

  6. Detectors (A,B,C) layout
    (zom in)

  7. Properties of strips/clusters in all 3 detectors
    detector A (most upstream) detector B (middle) detector C (most downstream)
    1 pedestals of working strips after ChipPedestal correction show in PDF files
    working strips U=153, V=152 (PDF) working strips U=148, V=144 (PDF) working strips U=89, V=53 (PDF)
    2 Seed strip ADC vs. cluster position (stripID)
    3 Seed strip ADC U=top, V=bottom, peak at ~600 is due to saturation
    4 Cluster energy in ADC units(over 3+1+3 strips), V/U ratio of Landau MPV is given below.
    5 Cluster location (top), U-V cluster energy correlation (bottom)
    6 Cluster provile U=top, V=bottom. Approximate unfolded true width in units of strip size is given below.
    sigU=0.45, sigV=0.6
    sigU=0.5, sigV=0.75
    sigU=0.7, sigV=1.0

  8. Conclusions:
    1. This analysis reproduces magnitude and trend of cluster energy seen by Frank. The cluster width is consistent as well.
    2. Gains (amplitudes) of U/V plane change between detectors: A V/U =1.2, B V/U =0.76, C V/U =0.45
    3. Lot of channels were dead, many had too small dynamic range
    4. True width (sigma) of cluster is below the strip width: AU=0.45, AV=0.6, BU=0.5, BV=0.75, CU=0.7, CV=1.0 *(strip width).
      It varies a due to different construction of strip boards.

    5. Used code is here