| 摘要 |
PURPOSE:To obtain an only desired specific ion without causing the necessity for troublesome regulating work, by providing a periodically changing means of intensity of the electric or magnetic field and detecting intensity of a charged particle substantially selected through a filter in accordance with a periodic change. CONSTITUTION:When only an ion B of the ions Pt and B generated from an ion source 11 is selected by a charged particle filter, said filter is set to intensity of the electric and magnetic field in accordance with mass and energy of said ion B. As a result, output voltage of a Hall element 18 is changed to saw tooth state in accordance with an input current, and output voltage of a differential amplifier 21 and an output current from an excitation power source 17 further intensity of the magnetic field between magnetic poles 13A, 13B are also changed to a saw tooth state. In accordance with a change of intensity of this magnetic field, a selective condition of the charged particle filter is also changed, and an ion passing through an opening of an emissive slit 15 is changed in accordance with intensity of the magnetic field. |
