Ion source having improved cathode
AssigneeInternational Business Machines Corporation
InventorsHolger Hinkel, Georg Kraus
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Abstract
A direct heated rod-shaped cathode for an ion source is provided with a region of reduced cross-section adjacent its negative end to maximize the path length of electron movement within the discharge chamber and to provide effective control of the cathode resistance in a region that is relatively free of sputtering erosion during use.
Claims3
An ion generator having a housing forming a chamber, means for supporting a cathode within the housing, means for establishing an electrostatic field between the cathode and the housing, positive and negative terminals for applying a DC voltage across opposite ends of the cathode to induce a heating current therein, and means for supplying a source of ionizable molecules into said chamber, wherein the improvement comprises:
- the cathode having a region of reduced cross-section with respect to the cross-section of the remainder of the cathode, said reduced cross-section region being located nearer said negative terminal than said positive terminal.
Dependencies are inferred from the claim text.