Elektronenbundel-kanonstelsel

PURPOSE: To provide an electron gun system with a high current cathode, which can be manufactured without greatly changing a production line to manufacture a usual electron gun system. CONSTITUTION: The first grid electrode of a hat type, located 30-80 μm from the emission surface of a high current cathode, has a width of 30-70 μm in an electron transition region, the second grid electrode 15 has a width of 250 μm or more in an electron transition region and the third grid electrode 14 has a width of 250-400 μm in an electron transition region on the input side. The first grid electrode, a fourth gird electrode 13 excluding a high current cathode device, the third grid electrode 14, the second grid electrode 15 and a holder 16 of the first grid electrode are assembled together on a device integral with a glass strip 17 and the first grid and the cathode device are connected to the holder 16 of the first grid. An opening member 20 is mounted on the input side of the third grid electrode 14.