In {HEAD ~ operation}, the laser beam 30 from the laser 12 is directed by {TAIL ~ the mirror} 14 to a focusing lens 16, which concentrates or focuses the laser beam 30 into the sintering nozzle 28 
In { HEAD ~ operation } , the laser beam 30 from the laser 12 is directed by { TAIL ~ the mirror } 14 to a focusing lens 16 , which concentrates or focuses the laser beam 30 into the sintering nozzle 28
OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH