GEANT321/gphys/ganni2.F

   1 *
   2 * $Id$
   3 *
   4 * $Log$
   5 * Revision 1.1.1.1  1995/10/24 10:21:21  cernlib
   6 * Geant
   7 *
   8 *
   9 #include "geant321/pilot.h"
  10 *CMZ :  3.21/02 29/03/94  15.41.21  by  S.Giani
  11 *-- Author :
  12       SUBROUTINE GANNI2
  13 C.
  14 C.    ******************************************************************
  15 C.    *                                                                *
  16 C.    *       Generates positron annihilation at rest                  *
  17 C.    *       (alias of GANNIR , directly called from GPAIRG)          *
  18 C.    *                                                                *
  19 C.    *    ==>Called by : GPAIRG,GPAIRM                                *
  20 C.    *       Author    M.Maire *********                              *
  21 C.    *                                                                *
  22 C.    ******************************************************************
  23 C.
  24 #include "geant321/gcphys.inc"
  25 #include "geant321/gctrak.inc"
  26 #include "geant321/gcking.inc"
  27 #include "geant321/gccuts.inc"
  28 #include "geant321/gconsp.inc"
  29       DIMENSION RNDM(2)
  30 C.
  31       KCASE = NAMEC(11)
  32       IF((IANNI.NE.1).OR.(EMASS.LE.CUTGAM)) THEN
  33          DESTEP = DESTEP + 2*EMASS
  34          GO TO 999
  35       ENDIF
  36       CALL GRNDM(RNDM,2)
  37       CT=-1.+2.*RNDM(1)
  38       ST=SQRT((1.-CT)*(1.+CT))
  39       PHI=TWOPI*RNDM(2)
  40       NGKINE=NGKINE+1
  41       GKIN(1,NGKINE)=EMASS*ST*COS(PHI)
  42       GKIN(2,NGKINE)=EMASS*ST*SIN(PHI)
  43       GKIN(3,NGKINE)=EMASS*CT
  44       GKIN(4,NGKINE)=EMASS
  45       GKIN(5,NGKINE)=1.
  46       TOFD(NGKINE)=0.
  47       GPOS(1,NGKINE) = VECT(1)
  48       GPOS(2,NGKINE) = VECT(2)
  49       GPOS(3,NGKINE) = VECT(3)
  50       NGKINE=NGKINE+1
  51       DO 10 J=1,3
  52    10 GKIN(J,NGKINE)=-GKIN(J,NGKINE-1)
  53       GKIN(4,NGKINE)=EMASS
  54       GKIN(5,NGKINE)=1.
  55       TOFD(NGKINE)=0.
  56       GPOS(1,NGKINE) = VECT(1)
  57       GPOS(2,NGKINE) = VECT(2)
  58       GPOS(3,NGKINE) = VECT(3)
  59 C
  60   999 END