Proposal for documentation

(Calorimeter example)

C18 - CAL Pedestals - Low Level Calibration

Description : Pedestals correspond to an ADC output for zero input to front-end electronics (FEE).  There is a pedestal value per gain (energy) range of each diode. Each pedestal is characterized by a centroid and a width of a distribution of a given (TBD) number of triggers. Since there are two diodes in each of the two crystal faces, we will have eight pedestal distributions per crystal. . In practice, pedestal values are defined as pedestal subtracted ADC values. In the SAS reconstruction software they are usually referred to as rails (TBR). Typical numbers are expected to be the order of 3000 while the width corresponds to the sigma of a Gaussian distribution fitted to the pedestals of a large number of events for each range of the diode. Typically, one expects width values to be much smaller than pedestals.

  Data Format:

 

Tower

Column

Layer

Face

Diode

ADC value

 

 

 

 

 

 

Ped

Width

 

0

0-11

0-7

0-1

0-1

0-4096

0-4096

Type

int

int

Int

int

Int

float

float

  Notes: Pedestals may change with temperature