Patent ID: 6724160
Filing Date: 2004-04-20
Classification: H01J

Abstract:
A method for providing a current-neutralized ion beam, the method comprising the steps of:(a) providing a gridless ion-source means for generating an ion beam and wherein said ion-source means includes an anode; (b) providing a discharge-supply means having a positive terminal and a negative terminal, wherein said positive terminal of said discharge-supply means is connected to said anode; (c) providing a hot-filament cathode-neutralizer; (d) providing a heater-supply means for generating a heater current, where said heater-supply means is connected to said cathode-neutralizer, and said heater current is sufficient to raise said cathode-neutralizer to an electron-emissive operating temperature beyond an emission threshold; (e) providing an electrical ground which may or may not be connected to earth ground; (f) connecting said cathode-neutralizer to a common circuit point with said negative terminal of said discharge-supply means, wherein said circuit point is substantially isolated from said electrical ground; (g) measuring a potential of said circuit point relative to said electrical ground; and (h) controlling said heater current so as to maintain said potential of said circuit point within a predetermined range of values.