| 摘要 |
PURPOSE:To obtain a well-controllable ion gun of IMA by impressing to a control electrode, added voltage consisting of the primary ion acceleration voltage to be preset according to the ions supplied to a sample and the voltage to be preset in a certain relation to the acceleration voltage. CONSTITUTION:An ion gun is composed of a cathode electrode 1, an intermediate electrode 2, an anode electrode 3 and a control electrode 4. The primary acceleration power supply 8 is connected to the electrode 3 while the control power supply 7 is connected to the electrode 4. The output voltage of the power supply 8 is set up by a voltage setter 11 while the output voltage of the power supply 7 is set up by an adder 13. The adder 13 produces voltage 3V by adding voltage V1 of setter 11 to voltage V2 of setter 12. In this way, the control voltage is changed in proportion to the primary ion acceleration voltage thus enabling to obtain a well-controllable ion gun of IMA. |
