The set of dedicated runs have runs with dedicated configurations (lacCalib_*, flecalib_*,fheCalib_*), has been collected during July 4-7, 2008 allowing to extract the calibration curves for LAC, FLE,FHE thresholds.
ULD thresholds were calibrated on the basis of all available runs having
- nominal ULD settings (5% below the saturation:nomSciOps,calibOps,vetoCalib,bkgNadir,bkgPrescaled) or
- low ULD settings (10% below the saturatinconSciOps,hldCalib,conBkgNadir,conBkgPrescaled).
From the measured threshold values for low and Hi(Mid) settings and the DAC settings, knwo from configuration files, the linear model (thresh = slope*DAC+offset) was defined for each calorimeter crtystal end and each threshold type. The parameters of the linear model ("dac slopes") were stored in the xml file dacSLopes_final.orbit.0708.xml which should be used to build the updated LAT configurations for subsequent upload to the instrument.
To validate the content of new dacSLopes file it was compared to the one actully in use. The results of comparizon is shown on following plots.
FLE linear model parameters
FHE linear model parameters
LAC linear model parameters
To test new dacSlopes file the set of new dac settings for FLE, FHE and LAC was generated, the plots below show the difference between new and old dac settings.
threshold calibration is based on nomSciOps and conSciOps runs.