Fermi Acceleration with Lorentz Scattering

The Fermi acceleration model was first used to describe how cosmic ray particles are accelerated to great speeds by interacting with moving magnetic fields. Since then, many variations of the model have been studied. We identify a new variation of the model where a multiple species plasma interacts with moving walls while undergoing interspecies pitch angle scattering. Due to the relationship between the mean free path for Coulomb collisions and the particle speed, the rate at which a particle is accelerated by the moving wall may be heavily dependent on its initial speed and the density of the background species. This would suggest that the system might be tuned with these parameters to produce favorable distributions of particles, such as a peaked energy distribution. A peaked energy distribution might optimize fusion reactivity or better characterize astrophysical phenomena.