Preparation of Electronic Cell Information

Subroutines ECAL_Reconst_Prep, HCAL_Reconst_Prep, HCAP_Reconst_Prep.

This part of program unpacks (if necessary) and fills the main input common blocks with coordinates and amplitudes of calorimeter hits.

To start the reconstruction COMMON / ECreconst / must be filled with:

NhitsE - Number of cells with non-zero amplitude in ECAL;

a_cellE(i) - Amplitude of calorimeter cell in physical units [GeV];

ny_layE(i) - Calorimeter longitudinal structure layer number;

x_cellE(i), y_cellE(i), z_cellE(i) - Cartesian coordinates of cell in [cm], the center of coordinate system suppose to be at the detector geometrical center (GEANT Master Reference Frame);

r_cellE(i), t_cellE(i), p_cellE(i) - Spherical coordinates of cell ($R \;[cm]$, $0 \;< \;\Theta\; < \;180, \; 0\; < \;\Phi\; < \;360 )$ [degree]; Zero of the $\Theta$ angle is at the Z+ axes.

The same information for HCAL - COMMON / HCreconst /: Nhits, a_cell(i), ny_lay(i), x_cell(i), y_cell(i), z_cell(i), r_cell(i), t_cell(i), p_cell(i) has to be filled also.

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energy_coeff1, energy_coeff2, energy_coeff - coefficients are used in this programs to convert GEANT energy losses to the physical scale (see initialization parameters description).

Hierarchy of cell amplitude scales:
1. Amplitude read from ADC (integer);
2. Amplitude in the detector energy losses units [GeV] (do not include absorber);
3. Amplitude in physical scale [GeV] - include absorber losses.

The second term is generated by GEANT and it is remember as cell amplitude before digitization. The detector electronic noise and non-uniformity must be added at this level i.e. before digitization.

Level 3 is used in the reconstruction.