One known way to improve the efficiency of glow discharge sputtering is to use {HEAD ~ magnetic fields} to confine {TAIL ~ electrons} to the glow region in the vicinity of the cathode/target surface 
to confine
One known way to improve the efficiency of glow discharge sputtering is to use { HEAD ~ magnetic fields } to confine { TAIL ~ electrons } to the glow region in the vicinity of the cathode / target surface
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH