Difference between revisions of "Gams reconstruction"

Revision as of 13:02, 5 September 2013

Short description of the reconstruction package developed for GAMS

(with changes and updates)

Package includes:

adcgam_bk.inc common with output reconstruction

phot_cell_cbk_mc.inc common with shower profile parameters

cphoto.inc common with control keys, flags and other aux. variables

addhits_lib.F generates hits based on shower library data

addhits_sim.F performs hits generation using fast simulation based on profile functions

isim.F main routine calling others to generate hits

recon_sim.F contains reconstruction package itself

guout.F call recon_sim() from here to get event reconstruction

gustep.F call isim(chdet,chsimopt) to simulate and store hits. Normally, after that particle stops in GUSTEP (ISTOP = 1) to avoid multiple counting

Files description:

adcgam_bk.inc Reconstruction common looks like:

Real:

energy_adcgam(1,i) - energy in GeV
     x_adcgam(1,i) - log. method x-coord (angular correction applied)
     y_adcgam(1,i) - log. method y-coord (angular correction applied)
     z_adcgam(1,i) - z-coord
    xc_adcgam(1,i) - center of gravity x-coord (no angular correction and global alignment - internal ref. syst.)
    yc_adcgam(1,i) - center of gravity y-coord (no angular correction and global alignment - internal ref. syst.)
  chi2_adcgam(1,i) - chi2

Integer:

  type_adcgam(1,i) - type of the gamma:
 = 0 default value
+= 1 or 2 for clusters selected by splitting single maxima shape
+= 10 for clusters selected from mutlimaxima island
+= 100 for LG clusters in hybrid detector
 = 50 + type1 + type2 for merged together subclusters 1 and 2 (transition case)

(hole size is hardcoded to 5x5 cells for PWO and 3x3 cells for LG)

  dime_adcgam(1,i) - number of counters in the gamma
    id_adcgam(1,i) - id of the cell with the max energy deposition:
                   = 10*col+row
 nadcgam - number of reconstructions in event
 (i = 1 ... nadcgam)

isim.F - control keys and options:

chdet = hybrid or lg, - simulate Hybrid (120x120cm pwo and LG outer part) or "regular" LG FCAL

chsimopt = simfast, libr or libs for fast profile simulation or to read clusters from library (sequentially or randomly)

addhits_sim.F and addhits_lib.F: generate response for

e+/e-/gamma - library read or simfast,

other types - for now simfast only:

MIP - gaussian energy deposition in single cell
neutral hadrons - parametrized ugly shape from GAMS,
                  probab. of shower is given by nulc. length
charged hadrons = neutral hadrons + MIP

 isim.F - flags and options:

zmcplane = 625.0506cm - FCal upstream surf. z

main settings are in init_sim_geom (file isim.F):

     min_energy = 0.1        - [GeV] clusters energy threshold
     global_gain= 1.000      - global energy gain, useful to quickly correct energy scale
     delch      = 4.         - minimum chi2 improvement sufficient for algorithm to decide to split 2 clusters from the signle maximum shape

     xm2cut     = 1.2        - min inv. mass over e cut to split hits
     minpk      = 9          - (in 10MeV units) minimum cell energy to be good for the peak of the island, note that this cut indirectly affects on cluster min energy
     chisq1     = 3          - min chi2 to try to split shape at preliminary stage
     chisq2     = 1.4 (was 0.4)  - min chi2 to try to split shape at final stage
     event_display = 0       - whether to run event display (option removed to allow hybrid)