| 摘要 |
PURPOSE:To generate an stable ion beam, by connecting one end of a reservoir holding liquid metal to the heating power supply of a fixed heater, detecting the heater service power and controlling a heating power supply in comparision with the set value. CONSTITUTION:A liquid metal such as gallium is placed inside a reservoir 1, a needle-shaped member made of tungsten is installed, while being allowed to pass through the bottom, and the other end of needle-shaped member is disposed oppositely against a cathode 5 at the each potential. A heater 6 is spot- welded to the reservoir 1. Positive high voltage is impressed from an accelerating power source 8 to the needle-shaped member, while a power source 11 for the sake of the lead-out electrode is applied to an oppositely installed lead- out electrode 11. A power detector 14 detects a service power to the heater 6, gives it to an arithmetic unit 16 through an insulating type signal transmission circuit 15, and compared with set standard power supply. A differential-mode signal changes the amplitude of a high-frequency oscillator 19 through a gate circuit 18 and is given to a rectifier circuit 21 through an insulating transformer 20. The heating temperature of the heater can be maintained constant by supplying the rectified output to the heater 6. |
