an electrical power source coupled to said {TAIL ~ light beam scanner} for {HEAD ~ powering} said scanner 
an electrical power source coupled to said { TAIL ~ light beam scanner } for { HEAD ~ powering } said scanner
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH