| 摘要 |
PURPOSE:To extract ion types other than gas component by using solid phase components as the ion source material and melting them and then supply them to discharge space. CONSTITUTION:A cathode 21 has a recess 14 that contains ion source material 12 and is comprised with a housing 15 in which a support section made of porous material such as porous tungusten is installed so that the melted ion source material 12 can be supplied to the space between an intermediate electrode 12 and the cathode 21. When the lower end of the housing 15 is exposed to plasma 9, the support section 11 reaches high temperatures. As a result, the ion source material 12 is melted, penetrated into the support section 11, evaporated, and the plasma 9 is formed as a part of discharge gas. At this state, ion extraction voltage is applied and an ion beam 10 is extracted using the ion source material 12. |
