Range Straggling of a Nonrelativistic Charged Particle

Abstract

The validity of the gaussian approximation for the range straggling, due to ionization and excitation, of a nonrelativistic charged heavy particle is investigated. Exact solutions are obtained which show that, in comparison with the usual theory: (a) the mean range of a particle is slightly increased; (b) the range distribution has a tail in the direction of shorter-than-average range; (c) the most probable range is slightly longer than the mean range. First a fictitious problem is solved, and then the transition to the real world is made.