{HEAD ~ The vacuum pump} 12 evacuates {TAIL ~ the interior} of the light source chamber 10 
evacuates
{ HEAD ~ The vacuum pump } 12 evacuates { TAIL ~ the interior } of the light source chamber 10
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH