GEANT321/gtrak/gnckov.F

   1 *
   2 * $Id$
   3 *
   4 * $Log$
   5 * Revision 1.1.1.1  1995/10/24 10:21:41  cernlib
   6 * Geant
   7 *
   8 *
   9 #include "geant321/pilot.h"
  10 *CMZ :  3.21/02 29/03/94  15.41.23  by  S.Giani
  11 *-- Author :
  12       SUBROUTINE GNCKOV
  13 C.
  14 C.    ******************************************************************
  15 C.    *                                                                *
  16 C.    *   This routine calculates the number of Cerenkov photons       *
  17 C.    *   produced per centimeter in the current medium.               *
  18 C.    *                                                                *
  19 C.    *   ==>Called by : GRANGI                                        *
  20 C.    *      Authors     R.Jones, F.Carminati ********                 *
  21 C.    *                                                                *
  22 C.    ******************************************************************
  23 C.
  24 #include "geant321/gcbank.inc"
  25 #include "geant321/gcjloc.inc"
  26 #include "geant321/gctmed.inc"
  27 #include "geant321/gcunit.inc"
  28 #include "geant321/gctrak.inc"
  29 #include "geant321/gckine.inc"
  30 #include "geant321/gconsp.inc"
  31 *
  32       PARAMETER (RFACT=369.81E9)
  33 *
  34 *   ------------------------------------------------------------------
  35 *
  36 * *** See whether we generate at least one photon
  37 *
  38       THRIND = GETOT/VECT(7)
  39       IF(Q(JINDEX+NPCKOV).LT.THRIND) THEN
  40          DP   = 0.
  41          GE   = 0.
  42       ELSEIF(Q(JINDEX+1).GE.THRIND) THEN
  43          PMIN = Q(JTCKOV+2)
  44          DP   = Q(JTCKOV+NPCKOV+1)-PMIN
  45          GE   = Q(JCURIN+NPCKOV)
  46          JMIN = 1
  47       ELSE
  48          JMIN = 1
  49          JMAX = NPCKOV
  50    10    JMED = (JMIN+JMAX)/2
  51          IF(Q(JINDEX+JMED).LT.THRIND) THEN
  52             JMIN = JMED
  53          ELSE
  54             JMAX = JMED
  55          ENDIF
  56          IF(JMAX-JMIN.GT.1) GO TO 10
  57          RATIO =
  58      +   (THRIND-Q(JINDEX+JMIN))/(Q(JINDEX+JMIN+1)-Q(JINDEX+JMIN))
  59          RATI1 = 1.-RATIO
  60          PMIN  = Q(JTCKOV+JMIN+1)*RATI1+Q(JTCKOV+JMIN+2)*RATIO
  61          DP    = Q(JTCKOV+NPCKOV+1)-PMIN
  62          GEMIN = Q(JCURIN+JMIN)*RATI1+Q(JCURIN+JMIN+1)*RATIO
  63          GE    = Q(JCURIN+NPCKOV)-GEMIN
  64       ENDIF
  65       DNDL = RFACT*(CHARGE**2)*(DP-GE*THRIND**2)
  66  999  END