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    User name glesener/suleiman

    Log entry time 18:19:13 on July15,2005

    Entry number 148081

    keyword=Setting Lumi HV

    Setting Lumi high voltages:
    ---------------------------
    
    Lumi HV channels are in the Right Arm-Bottom Crate, Slot 14.
    
    From the Hall A main menu choose "LeCroy HV."
    In LeCroy directory choose "Right Arm Bottom."
    Click button below "Lumi."  This brings up the Lumi high voltages.  Channels 
    0-7 are Blumis 1-8 and channels 8,9 are Flumis 1,2.
    
    Turn on HVs by clicking buttons to right of each channel and enter voltages in 
    the "Set V" bars.  Make sure HV/ON is selected at top of screen.
    
    The maximum HV is -1300V...do NOT exceed this limit.
    
    Check the ADC values and make sure they are around 45000 channels.  Changing 
    target, beam current will change the ADC value, so Lumi HVs will have to be 
    adjusted.
    
      For Carbon runs:  Start with -700V on all lumis, check ADC values, then 
    adjust the HV to get a mean ADC value of 45000 channels.
    
      For Helium runs: Start with -500V on all lumis, check ADC values, then adjust 
    the GV to get a mean ADC value of 45000 channels.
    
    A 100V adjustment will give you approximately a factor of 3 in gain.
    
    How to tell which Lumi is which:
    --------------------------------
    
    
    
    


    FIGURE 1