A solid plug 42 of electromagnetically lossy glass like ceramic material is provided which is situated within {HEAD ~ the passageway} 45 of a metallic casing 43 and joined to the inner wall of said casing 43 and also to the electrode 50 so that a plug to casing fusion joint 44 and a plug to electrode fusion joint 46, respectively, are obtained uniformly at all points of {TAIL ~ contact} between these respective members 
A solid plug 42 of electromagnetically lossy glass like ceramic material is provided which is situated within { HEAD ~ the passageway } 45 of a metallic casing 43 and joined to the inner wall of said casing 43 and also to the electrode 50 so that a plug to casing fusion joint 44 and a plug to electrode fusion joint 46 , respectively , are obtained uniformly at all points of { TAIL ~ contact } between these respective members
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD 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 OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH