Electron physics
Electrons are charged particles, and have a charge/mass ratio 2000 times greater than a proton. Electrons obey wave/particle duality principles. Electrons may be manipulated by both electrostatic and magnetic fields. Within the gun
column electrons are accelerated to very high velocities and relativistic correction factors are required for accurate computation.
An electron moving at charge 'e' with a velocity 'v' in the presence of both an electric field 'E' and a magnetic field 'B' experiences both an electric and magnetic force.
The total force acting on the electron is
F = e
E + ev x
B
Typical electron beam welding and processing systems utilise electrostatic forces for beam generation, and magnetic forces for beam manipulation and focusing.
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Typical electron gun column
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Electron optics are designed to manipulate the beam to optimise the EB process
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Electrostatic forces within the gun
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Electrons in magnetic fields move in curved paths
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Thermionic emission
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Magnetic focusing lens; schematic
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Rotation caused by magnetic lens
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Contact:
electronbeam@twi.co.uk
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2008
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