Stanford University

Stanford University, Radiological Sciences Laboratory

Study and design of B-field electron guns

The electron guns in a linear accelerator are typically not designed to work in a magnetic field. When a magnetic field is present it can disturb the path of the electons so that the beam is distrted or stopped from exiting the gun. When this happends the linear accelerator out drops to the point where it can no longer function.

The following image showsn the modelled behaviour of a beam of electrons as it is generated in, and moves through, a linear accelerator electron gun.

 

The following images show the effect of a magnetic field of differing strengths when it is either parallel to (=), or perpendicular to (T), the direction motion of the electrons in the gun.