Motion of a Charged Particle in an Electromagnetic Field

This Demonstration shows the motion of a charged particle in an electromagnetic field consisting of a constant electric field with components along the and axes and a constant magnetic field along the axis. The Lorentz force causes the particle to move in a helical orbit. Given the initial conditions, you can explicitly determine the equations of motion.

You can vary the radius of the helicoid and the drift velocity by modifying the parameters. The center of the circumference moves at the drift velocity, which is given by the vector product of the electric field and magnetic fields divided by the square of the magnetic field.