摘要 |
An x-ray tube has at least one approximately planar electron emitter and an emitter-cup cathode configured to provide an electron beam of substantially greater perveance and beam compression ratio than otherwise obtainable with conventional cathode designs. The cup is optimized for use in a line-focus, planar-anode tube and has a slot in which the emitter is situated, an adjacent face region which is planar and angled so as to properly form the initial electron beam, a recess to allow the initial electron beam to be accelerated without significant shaping, and an overhanging portion which completes the electron beam forming.
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