anchor.diff:          lint(j) = zlm - drift_length
         end if
       end if
  +
       !++  Transform back to particle coordinates with opening and offset
       if(x < 99.0d-3) then
         ! Include collimator tilt
  
positive.code:       x  = x + sin_mb(tiltangle) * c_length
        xp = xp - tiltangle
      end if
  
      ! For selected collimator, first turn reset particle distribution to simple pencil beam
      nprim = 3
  
negative.code:     x  = mirror * x
      xp = mirror * xp
  
      ! Shift with opening and offset
      x = (x - c_aperture/two) - mirror*c_offset
  
  