MGDRAW

The user must define locally a REAL*4 vector to fill the ntupla, XTUP. This declaration can be placed at the beginning of MGDRAW routine, just after the inclusion of all standard commons.

....
*
      PARAMETER (NNTUPLE=8)
      REAL*4 XTUP(nntuple)
*
....

In this routine the user must comment ALL the WRITE fortran cards, which are intended to write a file where all transport events are recorded: this is not usefull here, as the relevant information is stored in a basic ntupla of HBOOK.

Then we show only the relevant section relative to ENTRY BXDRAW. The meaning of the relevant variables in BXDRAW is the following:

*     Jtrack         = identity number of the particle                    *
*     Etrack         = total energy of the particle                       *
*     Am             = mass energy of the particle                        *
*     Cx,y,ztrck     = direction cosines of the current particle          *
*     Mreg           = region number before the boundary crossing         *
*     Newreg         = region number after the boundary crossing          *
*     xco,yco,zco    = coordinates of the particle at boundary crossing   *

In order to select the desired boundary, we remember that in our geometry description, the detector depth was defined as the crossing between region 3 and 4.

....


*======================================================================*
*                                                                      *
*     Boundary-(X)crossing DRAWing:                                    *
*                                                                      *
*     Icode = 1x: call from Kaskad                                     *
*             19: boundary crossing                                    *
*     Icode = 2x: call from Emfsco                                     *
*             29: boundary crossing                                    *
*     Icode = 3x: call from Kasneu                                     *
*             39: boundary crossing                                    *
*     Icode = 4x: call from Kashea                                     *
*             49: boundary crossing                                    *
*     Icode = 5x: call from Kasoph                                     *
*             59: boundary crossing                                    *
*                                                                      *
*======================================================================*
*                                                                      *
      ENTRY BXDRAW ( ICODE, MREG, NEWREG, XSCO, YSCO, ZSCO )
C-STA
      WRITE(*,*) 'BXDRAW ',icode,mreg,newreg,jtrack
     $     ,etrack,am(jtrack) 
      IF(MREG.EQ.3.AND.NEWREG.EQ.4) THEN          ! Select the desired boundary
         IF( JTRACK.EQ.10.OR.JTRACK.EQ.11 ) THEN  ! Select muons
            IF(ETRACK.GT.AM(JTRACK)) THEN         ! Muon has survived
               XTUP(1) = JTRACK
               XTUP(2) = ETRACK-AM(JTRACK)
               XTUP(3) = XSCO
               XTUP(4) = YSCO
               XTUP(5) = ZSCO
               XTUP(6) = CXTRCK
               XTUP(7) = CYTRCK
               XTUP(8) = CZTRCK
               CALL HFN(100,XTUP)
            ENDIF
         ENDIF
      ENDIF
C-END
      RETURN
*
      END IF
....