From Olga.Kodolova@cern.ch Sun Sep 16 21:11:53 2001
Date: Tue, 11 Sep 2001 10:38:25 +0200 (MET DST)
From: Olga Kodolova <Olga.Kodolova@cern.ch>
To: eno@physics.umd.edu, kunori@fnal.gov
Cc: gavrilov@iris1.itep.ru, Alexei.Oulianov@cern.ch, grandr@lav01.sinp.msu.ru,
     e@lav01.sinp.msu.ru
Subject: Re: hcal database (fwd)

  Hello Sarah and Shuichi
Alexei proposed the variant of hcal calibration database
description. Maybe it can be put on jetmet page as draft0 for
further discussion?
     best regards
             Olga

  HCAL database(s)
 
  1. Construction data.
      Response ratios collimated source / wire source for all
     scintillator tile geometries (about 600?).
  
     Quality control data... 
   Maybe one should ask the technical coordinators HB,HO,HE and HF
   which information can be provided from QC (data on sensitive elements-
   tiles,WLS,QF,etc)

 
  2. Test beam data.
 
  3. Calibration data. 
     Wire source calibrations of all layers (few times during 
     the entire life of the experiment - keep all data). Average 
     ADC signal, number of photoelectrons for each scintillator.
  
     Wire source calibrations of permanently connected layers.
     It should be done frequently. For example, during beam staging.
     It is rather stable signal.

     For HF one can store average ADC signal for each fiber bundle.
  
 
       LED/Laser calibration (timing?) and monitoring data
 
  4. Slow control data.
 
 
    5a Data from radiation monitors

 
 
  5b Data for ADC to GeV conversion for each readout channel 
     calculated from on-line calibrations and test beam data. 
     Maybe some independent calibration and monitoring the
     read-out channels electronics is planned?

 
        complete look up tables for HPD+ADC response linearization:
        2**9 * 16bit = 1kb per readout channel.
 
        Probably we'll have common basic LUTs for L1 and HLT.
        Then simpler scale corrections can be applied to compose the
         actual LUT values (probably different for L1 and higher levels) -
        see next item. 
 
  
  6. Corrections from off-line analysis.
 
     One energy scale correction per readout for normalization
     of different phi cells within each eta-ring and layer.
  
     One energy scale correction per eta-ring and layer (hcal
     layer or ecal). Can be different for L1 and HLT.
 
     Jet energy corrections. Probably several numbers per eta bin
     (currently, 3 numbers per 0.2 eta-bin). Different for L1 and HLT.
 
  7. Other programmable trigger parameters. Data on thresholds for
   each calorimetry cell in trigger.

 
  8. On-line physics data analysis.
  
     Keep recent data and some reference distributions? 
 
     Accumulate for each hcal cell (readout) number of hits above 
     threshold(s), average energy, dispersion of energy distribution.
 
     energy value for maximum of probability density
     distribution.
 
   For the latter we need to fill histograms - roughly 10-100 times more
   data than for simple averages. Not sure we need to do this for every
   individual readout. 
   But in the case of damages the shape of energy distribution is essential
   not a gaussian and for this case the most probable value can be more
   sensitive?
 
       
     Global and missing ET distributions? 
 
       9) Event pool from selected events should be available
          for first processing.
 
       10) Luminosity? (Maybe essential as it will changes from maximum
          to some value before the new injection)  
      Do we need a link to luminosity in the *HCAL* database?
      can be essential for high luminosity stuff where we can have 
      difference in two times in number of events per bunch depending
      on the time. MOreover noise and corrections connected with
      noise depend on luminosity. Radiation damages can depend on
      luminosity.
      Usage of pile-up for monitoring and calibration demands the
      knowledge of luminosity.

  Data 5-7 are to be written to an off-line database as run 
  conditions or whatever, so only current values should be kept 
  on-line.