| 摘要 |
PURPOSE:To improve the gas efficiency and to narrow the distribution width of the ion beam kinetic energy by adding the third cathode made of a capillary extending through an anode hollow section so as to feed the gas from the tip of the third cathode. CONSTITUTION:A through hole 16 is bored through the first cathode 13 having an axis coinciding with that of an anode hollow section 12, and the third cathode piercing this through hole 16 and partially extending through the anode hollow section 12 is made of a capillary. An anode 11, the first and third cathodes 13, 17 are supported by a stanchion body 20 made of an insulator through a stanchion also serving as a current passage, thus forming an electric connection section. In addition, other end of a pipe 24 connected to the gas source is fixed to a stanchion 10, the pipe 24 and a hole 25 bored through the stanchion 10 form a part of the gas passage connecting the third cathode 17 to the gas source, and the working gas fed from the gas source is made to flow out of the tip section located in the anode hollow section of the third cathode 17. |
