By subjecting a tungsten core wire in {HEAD ~ the electro deposit solution} containing {TAIL ~ the ternary carbonate} of 2.0 μm particles to cataphoresis, filament cathodes on each of which an oxide is coated in a thickness of 0.5, 1, 2, 3, 4, 5, 6, 7, or 8 μm are fabricated 
containing
By subjecting a tungsten core wire in { HEAD ~ the electro deposit solution } containing { TAIL ~ the ternary carbonate } of 2.0 μm particles to cataphoresis , filament cathodes on each of which an oxide is coated in a thickness of 0.5 , 1 , 2 , 3 , 4 , 5 , 6 , 7 , or 8 μm are fabricated
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH