ABSTRACT
When the particle distribution is very dilute, i.e., the particle density is low, we have as a limiting case that the electric and magnetic Àelds induced by the presence of the charged particles are negligible in comparison with the externally imposed Àelds. In such cases it sufÀces to consider the motion of the particles individually, and the problem is essentially reduced to investigating the motion of a charged particle with given initial position and velocity in a priori given electromagnetic force Àelds.
