{TAIL ~ Containers} 51, 52, and 53 of nitrogen, phosphine , and silane , respectively, are coupled to {HEAD ~ tube} 37 via pipe 39 under the control of flow controllers 54, 55, and 56, respectively 
{ TAIL ~ Containers } 51 , 52 , and 53 of nitrogen , phosphine , and silane , respectively , are coupled to { HEAD ~ tube } 37 via pipe 39 under the control of flow controllers 54 , 55 , and 56 , respectively
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH