Beam generation system for electron gun

摘要

The beam generation system has a triple electrode device with a cathode (1), a control electrode (3) and an anode (4), provided with a centre bore through which the electron beam (2) is directed from the beam generation space into a beam guidance space, with a beam cross-over point (9) within the bore. The anode is provided by an anode head (5) having a central bore (8) and an anode sleeve (6) containing at least one aperture stop (7). The bore in the anode head is matched to the beam diameter and is not more than 1 mm greater in diameter than the beam diameter.