High diffusion and fine focussing cathode for X=ray tube - has emitter with curvilinear shape focussing unit concentrating beam at anode impingement point

摘要

The cathode is for fine focussing high diffusion radiological tube. The cathode has a focussing electrode unit which supports an electron beam emitter. The emitter has a curvilinear shape. The focussing unit is designed to create a field which concentrates the electrode beam into an impact point on the anode. On the side facing the anode the focussing unit has a hollow part on its surface at the axis of symmetry. In the hollow is a slot situated in a plane perpendicular to the axis of symmetry. The slot is designed to receive a filament of closed curvilinear shape which emits a beam of electrons. Concentration of the electron beam on the anode is ensured by the surface.