The transverse dynamics of a nonrelativistic, mismatched charged-particle beam propagating through a continuous, linear focusing channel is calculated using the Fokker-Planck equation to represent the evolution of a coarse-grained distribution function in the phase space of a single beam particle. The relaxation rate and diffusion coefficient axe determined from a simple model of turbulence resulting from charge redistribution. The solution for the distribution function enables calculation of all transverse beam properties as a function of time, including the halo.
