Appts. generating longitudinal strips of energetic electron beams - has slotted conductive cylinders concentrically mounted around cathode for electrostatic shielding and aperture lens focusing

摘要

Appts. generating a longitudinal strip of energetic electrons includes a longitudinally extending electron-emitting cathode and conductive cylinders mounted coaxially with the cathode and concentrically disposed at successive spaced radial distances. Each cylinder has a narrow, longitudinal slot radially aligned with the slots of the other cylinders. A positive potential is applied to the innermost cylinder to control the extraction of electrons from the cathode and their egress as a longitudinal beam strip through the slot. An evacuated housing has a window radially aligned with the slots. An accelerating voltage field is established between the outermost cylinder and the window. The cylinders provide electrostatic shielding and aperture lens focussing.