Magnetic trap

Magnetic trap

. Charged particles can be trapped by Earth’s magnetic field. They bounce back and fourth between polar mirror points in either hemisphere at intervals of seconds to minutes, and they also drift around the planet on time scales of hours. As shown by Carl Størmer in 1907, with the trajectories shown here, the motion is turned around by the stronger magnetic fields near the Earth’s magnetic poles. Because of their positive and negative charge, the protons and electrons drift in opposite directions.

Copyright 2010, Professor Kenneth R. Lang, Tufts University