Wolfram Demonstrations Projecthttp://demonstrations.wolfram.com/An Open Resource of Interactive Mathematica VisualizationsCopyright 2009 Wolfram Demonstrations Project & ContributorsParticle Motion in a Penning Traphttp://demonstrations.wolfram.com/ParticleMotionInAPenningTrap/]]>http://demonstrations.wolfram.com/ParticleMotionInAPenningTrap/