[BLAST_SHIFTS] Night shift 10/28/2002

From: Genya (evgeni@mit.edu)
Date: Mon Oct 28 2002 - 09:19:44 EST


  We were taking runs for efficiency measurements with TOF R4-R7.
   Two runs are completed : 2370 - about 30 k
                            2371 - about 50 k
   The results are in the book.
   We noted that TOF7 events go mainly into CC2 instead of CC1, as regular
TOF_EFF.C script requires.
   Including CC2 into the script increases the number of events in TOF7 by at least
factor of 4-5.
   Also, noted that regular script has good time limits for pads, but very loosy ones
for start counter (1-4000). That lives in some fraction of accidentals. Including
strict cuts for start counter time improves efficiency by about 2 %.
   Measured efficiency is 93-95 % for TOF 4-6, and about 87-88% for TOF7.
   The ADC spectra indicate that, most likely, this is NOT real inefficiency, but
rather geometrical and random coincidences factors (ADC peaks look far above the
threshold).
     Genya



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