X-ray tube electron sources

摘要: An X-ray tube includes an emitter wire (18) enclosed in a suppressor (14, 16). extraction grid comprises number of parallel wires (20) extending perpendicular to the wire, and focusing (22) spaced apart at equal spacing (20). The are connected by means switches positive extracting potential or negative inhibiting potential, controlled so that any one time pair adjacent together form pair, which produce electron beam. position beam is moved switching different pairs potential.