Control of discharge initiation in high-intensity electron-beam generators for metal processing

Electric fields on the different components that are involved in the high-voltage performance of an electron gun used for welding are evaluated by a numerical method in order to reduce the risk of discharge breakdown during normal operation. A system composed of a tetrode tube placed in series between the power source and the electron gun and acting as a ballast resistor is developed to detect the initiation of a discharge in the electron gun and to stop its evolution toward a breakdown arc. The effect of beam interruption time on metal solidification during welding is addressed.<
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