HITS format

  The GEANT hits, i.e. the impact points at each detector entrance and exit, are recorded by the routine CMTHIT which is called from GUSTEP. The routine CMTHIT is used both for tracker and muon hits recording. The recordings are stored in standard GEANT HITS structure and can be retrieved by the routine GFHITS (see GEANT manual).

The hit format is defined in the title bank TKHT in //titl/tgeom13 as listed below. The information stored is the space point, particle direction and momentum (words 1-7) in global CMS system, the entrance and exit point coordinates in the local detector system (GEANT volume local system), deposited energy, time of flight and the radiation length particle has experienced so far.

 
*DO  TKHT  13   -c4/60  #.TracKer /Muon hit definition
     17                           #.No. of hit elements
   #. NAMESH  ORIG  FACT  NBITSH
  1 :X_G    2000.0  5.E5    0     #.VECT(1) at volume entrance (cm)
  2 :Y_G    2000.0  5.E5    0     #.VECT(2) at volume entrance
  3 :Z_G    2000.0  5.E5    0     #.VECT(3) at volume entrance
  4 :DIRX      1.0  1.E9    0     #.VECT(4) at volume entrance
  5 :DIRY      1.0  1.E9    0     #.VECT(5) at volume entrance
  6 :DIRZ      1.0  1.E9    0     #.VECT(6) at volume entrance
  7 :P         0.0  1.E6    0     #.VECT(7) at volume entrance (GeV)
  8 :TYPE      0.0  1.0     0     #.particle type
  9 :Xin     250.0  1.E6    0     #. enter point in detector element (cm)
 10 :Yin     250.0  1.E6    0     #.(detector element coordinate system: LCS)
 11 :Zin     250.0  1.E6    0     #.
 12 :XOUT    250.0  1.E6    0     #.exit  point from detector element (LCS)
 13 :YOUT    250.0  1.E6    0     #.
 14 :ZOUT    250.0  1.E6    0     #.
 15 :dEdX      0.0  1.E9    0     #.deposited energy, (GeV)
 16 :T_OF      0.0   10.    0     #.time_of_flight
 17 :RADL      0.0  1.E6    0     #.material traversed so far (in rad. lengths)

The coordinates and vector orientation transformation from local to global system and vica versa can be made by the GEANT routines GDTOM and GMTOD, respectively (see GEANT manual).