Electrodes are disposed in {TAIL ~ the medium} and are closely spaced such that {HEAD ~ the application} of a high voltage will cause arc discharge across the same 
Electrodes are disposed in { TAIL ~ the medium } and are closely spaced such that { HEAD ~ the application } of a high voltage will cause arc discharge across the same
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH