[Halld-pid-upgrade] [Revised Logentry] DIRC bar-by-bar diagnostics: early Fall 2019

[jrsteven at jlab.org]

Logentry Text:
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Based on runs 70817-70848, fully processed on the offline, bar-by-bar diagnostic plots of Nphotons, HitTime, HitTimeResidual, PixelHitMap (direct and reflected) are attached to the following DocDB page https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=4287 (the files are quite large...).  Each page of these documents corresponds to a bar (0-47) and the panels correspond to 40 (5 cm wide) bins in the X position of extrapolated tracks at the DIRC plane.

Summary: The south (lower) OB yields and hit maps look reasonable, compared with last Spring.  The north (upper) OB looks reasonable for the bar box just above the beam (bars 24-35), but starting with bar 36+ (the uppermost bar box) the photon yield and hit patterns are concerning.  Further investigation is needed to check that calibration of other detectors or some analysis cuts are not somehow losing photons from this bar box.

A reminder of the DIRC geometry (and bar numbering) can be found at https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=3717, which may be helpful in comparing the different pages of the documents linked in DocDB above.


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This is a plain text email for clients that cannot display HTML.  The full logentry can be found online at https://logbooks.jlab.org/entry/3752805
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