公开(公告)号：US3683235A

公开(公告)日：1972-08-08

申请号：US3683235D

申请日：1970-07-17

Applicant: EMI LTD

Inventor： PHILLIPS GRAHAM ,  PERRING DUDLEY

IPC: H01J23/083 ,  H01J25/20 ,  H01J23/08

CPC classification number: H01J23/083 ,  H01J25/20

Abstract: An electron discharge device includes a cathode for producing electrons, a target for collecting said electrons and an electron focusing system for focusing the electrons from said cathode into a beam directed to said target. The focusing system includes a member having an aperture for the passage of the beam and a charge retaining surface surrounding said aperture on which in operation of the tube unfocused electrons from said cathode impinge, said surface having such a coefficient of secondaryelectron emission for the energy of the cathode electrons under the rated operated conditions of the device that unfocused electrons tend to cause said surface to charge to a potential which will focus said electrons to pass through said aperture.

Abstract translation: 电子放电装置包括用于产生电子的阴极，用于收集所述电子的靶和用于将来自所述阴极的电子聚焦到指向所述靶的光束的电子聚焦系统。 聚焦系统包括具有用于光束通过的孔的构件和围绕所述孔的电荷保持表面，其中在管的操作中，未将来自所述阴极的电子聚焦，所述表面具有这样的二次电子发射系数 在未被聚焦的电子的器件的额定工作条件下阴极电子的能量倾向于使所述表面充电到将使所述电子聚焦通过所述孔的电位。