subroutine target(q, en0, x0, y0, z0, thx0, thy0,txin1,txin2,
     &     enp, x, y, z, thx, thy, xsig, thscat,
     &     scflag, nRef, zt1, pl, totrot,scwgt) !bec

      implicit none

      include 'const.inc'

      integer scf, scflag, nRef
      integer i, j, n, k
      parameter(n=50)
      double precision q, en0, x0, y0, z0, thx0, thy0,scwgt
      double precision lam, thtestx, thtesty, zt1 ! zt1 starting pos of target 1
      double precision txin1, txin2, zlm, pl, totrot, rotang
      double precision x, y, z, thx, thy, ep, enp
      double precision xi(n), yi(n), zi(n), thxi(n), thyi(n), eni(n)
      double precision xs(n), ys(n), zs(n)
      double precision xo(n), yo(n), zo(n), thxo(n), thyo(n), eno(n)
	double precision xsig,thscat
	double precision, external :: rsqrt,ratan
	logical rfailflg

c 
      lam = 2.*pi*h_par/rsqrt(2.*m_n*en0) ! Ang
      thtestx = gtindexx*lam
      thtesty = gtindexy*lam
c

	rfailflg = .false.
      xsig = -1.d6
      thscat  = -1.d6
      scf = 0
      scflag = 0
      nRef = 0
	totrot = 0.d0
	rotang = 0.d0

      zlm = z0 +  tarz

      if((x0.ge.txin1.and.x0.le.txin2).and.
     &     (y0.ge.tary1.and.y0.le.tary2)) then
         xi(1) = x0
         yi(1) = y0
         zi(1) = z0
         thxi(1) = thx0
         thyi(1) = thy0
         eni(1) = en0
         pl = 0

         do j=1, n		! loop through multiple scatterings
            if (j.ge.2) then
               xi(j) = xo(j-1)	! starting position now at last ending position
               yi(j) = yo(j-1)
               zi(j) = zo(j-1)
               thxi(j) = thxo(j-1)
               thyi(j) = thyo(j-1)
               eni(j) = eno(j-1)
            endif


C  load current position into scatt.f subroutine, check for scattering, do 
C    reflections and return new positions, angles, energy
            call scatt(q, eni(j), xi(j), yi(j), zi(j),thxi(j), thyi(j),
     &           txin1, txin2, tary1, tary2, zlm,
     &           xs(j), ys(j), zs(j), scf,
     &           eno(j), xo(j), yo(j), zo(j), thxo(j), thyo(j), 
     &           xsig,thscat,lam,rfailflg,scwgt)

		if (rfailflg) goto 110		! neutron is lost through wall
            scflag = scflag + scf  !  
c         scf is used in scatt,f to indicate if scatter position is inside
c             target (1) or outside target (0)

c      update rotation  -- need begining and ending positions and energy
		if (scf.eq.1) then
		   call rotation(eni(j),xi(j),yi(j),zi(j),xs(j),ys(j),
     &            zs(j),zt1,rotang)
	  pl=rsqrt((xs(j)-xi(j))**2+(ys(j)-yi(j))**2+(zs(j)-zi(j))**2)+pl
		   totrot = totrot + rotang
		   call rotation(eno(j),xs(j),ys(j),zs(j),xo(j),yo(j),
     &            zo(j),zt1,rotang)
	  pl=rsqrt((xo(j)-xs(j))**2+(yo(j)-ys(j))**2+(zo(j)-zs(j))**2)+pl
		   totrot = totrot + rotang
		else
			if (eno(j).ne.eni(j)) write(6,*) ' no scat but Ei.ne.Eo '
		   call rotation(eno(j),xi(j),yi(j),zi(j),xo(j),yo(j),
     &            zo(j),zt1,rotang)
	  pl=rsqrt((xo(j)-xi(j))**2+(yo(j)-yi(j))**2+(zo(j)-zi(j))**2)+pl 
		   totrot = totrot + rotang
		end if

c		if (j.gt.1) then
c		write(6,*) '      target ', j, rotang, totrot	
c		write(6,*) xo(j),yo(j),zo(j)
c		write(6,*) scf, rotang, totrot
c	    write(6,*) '      pl ',pl
c		end if

cccc		end rotation update

c   below is somewhat redundant because of rflx,y in scatt.f, but if you set rflx,y=1
c       in scatt.f, then this is needed.  So leave in.
	   if ((thxo(j).eq.-1*thxi(j)).and.(abs(thxo(j)).gt.thtestx)) then
            x = -1.d6
            y = -1.d6
            z = -1.d6
            thx = -1.d6
            thy = -1.d6
            enp = -1.d6         
	      exit
         endif
	   if ((thyo(j).eq.-1*thyi(j)).and.(abs(thyo(j)).gt.thtesty)) then
            x = -1.d6
            y = -1.d6
            z = -1.d6
            thx = -1.d6
            thy = -1.d6
            enp = -1.d6         
	      exit
         endif
c
            nRef = nRef + 1

	if (j.gt.49) write(6,*) ' j,en, xsig ',j,eni(j), xsig
	if (j.gt.49) write(6,*) ' x,y,z ',xo(j),yo(j),zo(j)


            if(zo(j)-zlm.ge.0) then
               x = xo(j)
               y = yo(j)
               z = zo(j)
               thx = thxo(j)
               thy = thyo(j)
               enp = eno(j)
               exit	!  Jump out of loop
            endif
         enddo

      else
         x = -1.d6
         y = -1.d6
         z = -1.d6
         thx = -1.d6
         thy = -1.d6
         enp = -1.d6
      endif
	
	goto 111

 110   continue
	   x = -1.d6
         y = -1.d6
         z = -1.d6
         thx = -1.d6
         thy = -1.d6
         enp = -1.d6
c	write(6,*) ' rfail ', thxi(j),thxo(j)
c	write(6,*)  thyi(j),thyo(j)
c	write(6,*) thtestx,thtesty

 111      return
      end