FAQ The Electron Beam

In an electron beam welder, electrons are “boiled off” as current passes through a filament which is in a vacuum enclosure. An electrostatic field, generated by a negatively charged filament and bias cup and a positively charged anode, accelerates the electrons to about 50% to 80% of the speed of light and shapes them into a beam. Due to the physical nature of the electrons – charged particles with an extremely low mass – their direction of travel can be easily influenced by electromagnetic fields. Electron beam welders use this characteristic to electromagnetically focus and very precisely deflect the beam at speeds up to 10 kHz. Recent machine developments make it possible even to go up to 200 kHz. With today’s CNC controls, the beam focus as well as the beam deflection are part of the weld schedule and can be variably programmed along with other process parameters.