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 = eE + ev x B

Typical electron beam welding and processing systems utilise electrostatic forces for beam generation, and magnetic forces for beam manipulation and focusing.

Typical electron gun column

Electron optics are designed to manipulate the beam to optimise the EB process

Electrostatic forces within the gun

Electrons in magnetic fields move in curved paths

Thermionic emission

Magnetic focusing lens; schematic

Rotation caused by magnetic lens

Contact: electronbeam@twi.co.uk