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Single Module Charge Timestamp Correction Factors

kwresilo edited this page Feb 4, 2024 · 7 revisions

Correction factors are required to account for the time delay between PPS reset being sent out and the reset actually taking place. To obtain the correction factors, we can leverage the fact that during single module commissioning data packets, called external triggers, were embedded in the charge read-out (CRO) datastream whenever the light read-out (LRO) triggered. Packet timestamps can then be recalculated using ts_cor = ts_raw - c1/(1+c2) by setting the values of c1 and c2 in the corresponding yaml yamls/module{0,1,2,3}_flow/reco/charge/TimestampCorrector.yaml.

Procedure: Timestamps correction factors are extracted by comparing the timestamps of matched light triggers (LRO datastream) and external triggers.

  1. Run light and charge reco workflow (the timestamp correction factors should all be set to 0 in TimestampCorrector.yaml).
  2. Run charge-light matching workflow.
  3. Using the reference between light/events/data and charge/ext_trigs/data datasets, plot the difference between light event timestamp and external trigger timestamp for CL matched events for each io group separately (2 io groups per module). You should obtain a plot such as the one shown below, where c1 = slope and c2 = y-intercept). Example code can be found in global/cfs/cdirs/dune/users/kwresilo/ana/PACMAN_ts_corr.ipynb.
image

Values extracted for modules 1-3:

Module # io # c1 c2
Module 1 io1 -11.0742 -1.691e-7
Module 1 io2 -10.9233 5.493e-7
Module 2 io1 -12.6752 4.871e-7
Module 2 io2 -12.4990 2.123e-6
Module 3 io1 -12.6262 3.359e-6
Module 3 io2 -12.5452 -6.340e-7
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