HCal Gain Calibration
Gain calibration constants have units [ADUc/pixel], where ADUc are ADC unit in calibration mode and a pixel is defined as the distance of two adjacent photoelectron peaks. The constants are made available in the database in folder
/cd_calice/Hcal/gain_constants
These calibration parameters are temperature dependent. The slopes dGain/dT for each channel are stored in the database folder
/cd_calice/Hcal/gain_slopes
Every entry gets tagged to allow permanent reference. Users are encouraged to use tags rather than the HEAD, i.e. make sure they know which assumptions are valid on the constants they use.
Tag description: gain_constants
Tag 
Time / HV Period 
Description 
ahc_gain_constants_001 
2006  2009 
Gain values extracted from linear fit to CERN 2007 measurements and extrapolated to 0 degrees centigrade. 
ahc_gain_constants_002 
C06 
same as ahc_gain_constants_001 
C07 
Average of all good gain measurements from this period, modules 1, 2, 14, 25 excluded (runlist_ahc_gain_constants_002_C07.txt). Modules 1, 2, 14, 25: Average of gain measurements from DESY recalibration (runlist_ahc_gain_constants_002_C07_DESY_recalib.txt) 

F081 
Average of all good gain measurements from this period. runlist_ahc_gain_constants_002_F081.txt 

F082 
Average of all good gain measurements from this period. runlist_ahc_gain_constants_002_F082.txt 

F083 
Average of all good gain measurements from this period. runlist_ahc_gain_constants_002_F083.txt 

F084 
Average of all good gain measurements from this period. runlist_ahc_gain_constants_002_F084.txt (runs from 2009 are not used yet) 

ahc_gain_constants_003 
2006  2009 
Same as ahc_gain_constants_001, added default value to collection (default = 400) 
ahc_gain_constants_004 
2006  2009 
Same as ahc_gain_constants_002, added default value to collection (default = 400) 
ahc_gain_constants_005 
2006  2009 
Same as ahc_gain_constants_004 
C10 
Values from C07 

ahc_gain_constants_006 
2006  2009 
Same as ahc_gain_constants_004 
C10 
Values extracted by Clemens 

C11 
Values from C07 

ahc_gain_constants_007 
2006  2009 
Same as ahc_gain_constants_004 
C10 
Same as ahc_gain_constants_006 

C11 
TODO: get the information from provider? 

ahc_gain_constants_008 
2006  2009 
Same as ahc_gain_constants_004 
C07 
constants same as ahc_gain_constants_004, and the reference temperature has been corrected with Median Filter by Sergey 

C10 
Same as ahc_gain_constants_006 

C11 
Same as ahc_gain_constants_007, and extended, available for the whole year 
Tag description: gain_slopes
Tag 
Time / HV Period 
Description 
ahc_gain_slopes_001 
2006  2009 
Absolute slopes extracted from linear fit to CERN 2007 measurements. 
ahc_gain_slopes_002 
C06 
same as ahc_gain_slopes_001 
C07 
For each channel: slope = 1.7%/K (average relative dependence) * gain constant (from ahc_gain_constants_002) 

F081 

F082 

F083 

F084 

ahc_gain_slopes_003 
2006  2009 
Same as ahc_gain_slopes_001, added default slope to collection (default = 0) 
ahc_gain_slopes_004 
2006  2009 
Same as ahc_gain_slopes_002, added default slope to collection (default = 0) 
ahc_gain_slopes_005 
2006  2009 
Same as ahc_gain_slopes_004 
C10 
Values from C07 

ahc_gain_slopes_006 
C06  F083 
Same as ahc_gain_slopes_004 
F084 
For each channel: slope = 1.6%/K (average relative dependence) * gain constant (from ahc_gain_constants_006) 

C10 
For each channel: slope = 1.7%/K (average relative dependence) * gain constant (from ahc_gain_constants_006) 

C11 
value from C07 

ahc_gain_slopes_007 
C06  F083 
Same as ahc_gain_slopes_004 
F084 
Same as ahc_gain_slopes_006 

C10 
Same as ahc_gain_slopes_006 

C11 
TODO: get the information from provider? 

ahc_gain_slopes_008 
C06  F083 
Same as ahc_gain_slopes_004 
C07 
Same as ahc_gain_slopes_004, and updated for layers 12,22,28,29 by Segey. Slope = (0.017) * gain(27), new Slope =  gain(T_ref)/((27T_ref)*(0.017)1)*(0.017). (gain constant and reference temperature are from ahc_gain_constants_008) Bug in default value 

F084 
Same as ahc_gain_slopes_006 

C10 
Same as ahc_gain_slopes_006 

C11 
Same as ahc_gain_slopes_007, and extended, available for the whole year 

ahc_gain_slopes_009 
C06  F083 
Same as ahc_gain_slopes_004 
C07 
Same as ahc_gain_slopes_004, and updated for layers 12,22,28,29 by Segey. Slope = (0.017) * gain(27), new Slope =  gain(T_ref)/((27T_ref)*(0.017)1)*(0.017). (gain constant and reference temperature are from ahc_gain_constants_008) 

F084 
Same as ahc_gain_slopes_006 

C10 
Same as ahc_gain_slopes_006 

C11 
Same as ahc_gain_slopes_007, and extended, available for the whole year 
outdated gain calibration folders
The tags of some outdated gain calibration folders are still listed here.
Measurement
comming soon...
The documentation of the tools used to extract the gain values from the binary files can be found in the section GainOnTheGrid.