Method for controlling emission current of electron source and electron source with control of emission current

摘要

The method regulates the emission current of an electron source (1,2,3) at a high voltage potential. A measurement signal for the emission current is generated at a low voltage potential. A resulting regulating signal at low voltage potential is optically fed to a high voltage potential regulator device. The regulating signal is preferably fed to the regulator via an optical fibre or an optical waveguide. A regulated electron source has an electron emitting cathode (1), a control electrode (2), an anode (3) and a high voltage source (4) between the anode (3) and the cathode (1). An electronic regulator circuit (6,7) in the high voltage circuit of the high voltage source (4) controls the electron flow. A low voltage potential circuit (5) measures the electron flow and generates a control signal. The latter is fed optically to the regulation circuit.