| 摘要 |
PURPOSE:To obtain a high frequency ion source which can supply electron without being accompanied by a sudden rise of gas pressure by preparing a sub-discharge chamber with higher gas pressure, as well as a main-discharge chamber. CONSTITUTION:In this high frequency ion source, Xe gas is introduced into a sub-discharge chamber 10 in which pressure is higher than in a main-discharge chamber 7, from gas introducing system 5. Setting up the pressure in the sub- discharge chamber 10 to such a degree that initial ionization plasma can be generated, enables naturally ionized electrons to be accelerated in the peripheral direction by high frequency electric field induced with an induction coil 6 and to collide with Xe gas to generate the ionization plasma. The ionization plasma generated in the sub-discharge chamber 10 lows into the main-discharge chamber 7. Electrons in the ionization plasma flowing into the main-discharge chamber 7 collide with Xe gas to generate ionization plasma. Thus Xe<+> ions are induced/ accelerated out of ionization plasma by electrodes 2, 3, and 4, and then released outside from the high frequency ion source. |
