Magnetic Field

Perhaps the most complicated force available in CindyLab is the Lorentz force. Whenever a charged particle enters a magnetic field with nonzero velocity, the particle's path is perturbed. The magnetic field causes a force orthogonal (at right angles) to both the direction of movement and the magnetic field. The force is proportional to three quantities: the charge of the particle, its speed, and its velocity. For instance, if an electron moves in a magnetic field without being subject to any additional forces, it will move in a circular path. If friction is present, the path will be a spiral.

In CindyLab one can add magnetic fields that are orthogonal to the drawing surface. Magnetic fields are polygonal regions that are added just as in Polygon mode. The exact relation between the fieldstrength of the field, the velocity of the particle, its charge, and the resulting force is given by the following formula:

Since the field is assumed to be orthogonal to the drawing surface, it will result in a force that is orthogonal to the movement of the particle. A charged particle will therefore move along a circular path. The following picture shows the trace of a charged particle that is shot into a region of a magnetic field.