ToF Online Calibrations

The TAC (Time to Amplitude Converter) calibration consists of parametrizing the time response of the DECAF by using different known time delays from the DDG. A fit is made to the DECAF vs DDG delay curve and the fit parameters are stored in the online database together with the covariance matrix.
For the QIE calibrations, known charges are injected to study the CAFE card response and linear fits are performed to the plots of charge vs CAFE counts. The results of these linear fits then go to the online database as well.

TAC calibrations are analyzed and stuffed into the Online Data Base by an online consumer, and then the pager person is only required to check the results of the calibration using DBANA and to keep a record of the TAC calibration taken, with their date and run number.


For the moment, checking the results of an online calibration can be done as follows:

• Checking a QIE calibration
  • Run DBANA and look at the QIE plots for the run you want to check.
  • Typical DBANA QIE plots are: QIE Slopes, Errors and Offsets and QIE Pedestals
• Checking a TAC calibration
  • Find out the run number of the TAC calibration you want to look at
  • You can find TAC calibration runs using the Run Summary page
    • Run Type 47 = ToF TAC calibration
    • Run Type 51 = ToF QIE calibration
  • Check the calibration log file for channel failures. The log file is in /cdf/people1/cdfdaq/consumers/log and it looks like runTacCalib_"RUNNUMBER"_"DATE"_"USER".log. To find the number of failing channels, look for the string "TOF TAC CALIBRATION RESULT".
  • Run DBANA and look at the TAC plots.
  • Typical DBANA TAC plots are: TAC Parameters, TAC Pedestal Minima/Maxima and TAC Pedestal for Experts

Useful links:

• Data Base Browser
• Run Summary
• DBANA
• YMON

The shift crew will run the ToF online calibrations whenever possible, usually between stores. Online calibration procedures can be found in:

• ToF QIE
• ToF TAC

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