means for delivering the energy from the source to {HEAD ~ the inner surface} of {TAIL ~ the tubular portion} 
of
means for delivering the energy from the source to { HEAD ~ the inner surface } of { TAIL ~ the tubular portion }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL