Thermionic cathode
 A thermionic cathode for an electron beam device is provided which comprises a first layer of thermoelectron emissive compound sharpened towards a point, a third layer of metal of high melting point and a second layer of reaction barrier interposed between the first and third layers, current terminals being attached to said third layer. According to the invention, a thermionic cathode capable of emitting stable electron beams of high intensity for a long period of time can be manufactured. 
Denki Kagaku Kogyo Kabushiki Kaisha
H
H01J
inventional
Akira Shuzo Masaji Hideo
Miyai Watanabe Ishii Hiraoka