Efficiency - HV and Thresholds scan on the GIF beam at CERN  
(GIF source OFF, Gas "old" Ar(30%)CO2(50%)CF4(20%) )


  • Efficiency.

  • - Efficiency per channel for each plane, calculated as ratio hit/track, when for the given plane and channel
    the track was measured by the beam chambers and given plane has zero or only one hit.
    - The efficiencies for the most 3 populated channels per plane are presented at different (actual) HV and thresholds (see the Plot .)
  • Thresholds and runs used.

  • - The tables below are the threshold codes selected for scan. The higher code corresponds to lower threshold. On the plot above these tables are marked as THR1,2 and 3. All chips have the time delay code 7. Threshold in fC vs threshold code used in the tables presented on the Plot .
    Table 1 (THR 1) Minimum thresholds (as oscillations free)
    ------------------------------------------------------------
    Card # \ DAC #  D0      D1      D2      D3      D4      D5
    ------------------------------------------------------------
    1               185     185     175     145     150     155
    2               180     160     140     140     140     140
    ------------------------------------------------------------
    

    Table 2 (THR 2)
    ------------------------------------------------------------
    Card # \ DAC #  D0      D1      D2      D3      D4      D5
    ------------------------------------------------------------
    1               175     175     165     135     140     145
    2               170     150     130     130     130     130
    ------------------------------------------------------------
    

    Table 3 (THR 3)
    ------------------------------------------------------------
    Card # \ DAC #  D0      D1      D2      D3      D4      D5
    ------------------------------------------------------------
    1               165     165     155     125     130     135
    2               160     140     120     120     120     120
    ------------------------------------------------------------
    
    - The runs used (GIF source OFF, measurements done on July 10-11, beam is muons of 25 GeV, see Logbook 1, page 220). Each run has about 5,000 events.
    -------------------------------------------------------------------------------
    RUN #   HV, kV      THR table      HV actual, kV       
            (nominal)
    -------------------------------------------------------------------------------
    
    344     3.8         1          3.643   3.787   3.718   3.801   3.740   3.711
    345                 2
    346                 3
    
    350     3.85        1          3.689   3.838   3.772   3.848   3.787   3.760
    351                 3
    353                 2
    
    359     3.9         1          3.738   3.892   3.821   3.894   3.840   3.811
    360                 2
    361                 3
    
    365     3.95        1          3.789   3.943   3.872   3.945   3.882   3.860
    366                 2
    367                 3 
    
    368     4.00        1          3.838   3.994   3.926   3.989   3.926   3.916
    369                 2
    370                 3
    
    371     4.05        1          3.887   4.033   3.984   4.041   3.977   3.965
    372                 2
    373                 3
    
    -------------------------------------------------------------------------------
    


    Last modified: Mon May 31 12:30:00 CST 1999

    teren@fnal.gov