| 摘要 |
PURPOSE:To improve the gas efficiency and to narrow the distribution width of the ion beam kinetic energy by forming two anodes, long and short, and by applying the highest potential to the short anode and the lowest potential to a cathode with an ion takeout through hole so as to introduce the gas into the space encircled by individual electrodes. CONSTITUTION:The short first electrode 21 with a piercing hollow section 23 and the second anode 22 are coaxially arranged next to each other, the first anode 21 is applied with the highest potential and the second anode 22 is applied with a potential lower than that of two cathodes, and the second cathode 11 having a through hole 9 bored coaxially with the axis of two anodes is fixed to a vacuum container 5 and is grounded. The other end of a pipe 14 connected to a working gas source is fixed to a stanchion 13, and the pipe 14 and a hole 15 bored through the stanchion 13 form a gas feed passage to the rear of the first cathode 10, then the fed gas passes through the gap between individual electrodes and is fed into the space encircled by individual electrodes. |
