Electron in a magnetic-mirror trap
What the animation shows
The electron follows a helical orbit along the magnetic field between two coaxial coils. It reflects where the field becomes stronger near either coil, then returns through the central region. The displayed orbit uses a 50° pitch angle and a mirror ratio of approximately 2.2.
Particle tracing in the coil field
The trajectory is computed with a Boris pusher in the Biot–Savart field of ideal thin current loops. In the adiabatic limit, increasing field strength converts parallel motion into transverse motion until the electron reflects. The research page explains the mirror condition and loss cone and includes an interactive version of the model.