How does electrons move in magnetic fields?

To investigate this question, the following experimental setup can be used:
A electron gun produces an electron beam. This beam is perpendicular to the b-field of the Helmholtz coils. Neongas makes the trajectory of the electrons visible.
experimental setup for deflection of electrons in magnetic fields, also for determination of the specific charge of an electron.diagram of the experimental setup to investigate the deflection of electrons in magtic fields.