Particle size determination for alpha-emitters using CR-39

This project is to develop methods to retrospectively determine the size of alpha-emitting particles that have been collected on personal air samplers. The alpha radiation from such particles produces a cluster of tracks on the surface of an etched nuclear track detector, CR-39. The number of tracks in a cluster, as well the diameter of the cluster, are dependent on several factors: the diameter of the hot particle, the distance between the particle and the CR-39 surface, the composition of the particle, and the alpha-particle energy.The dependence of the alpha-emitting particle size and the number of registered tracks were revealed, and produced predictions of the track density distribution observed on the CR-39 plastic. There is a good fit between the simulation of track density observed on the CR-39 and the tracks arising from uranium oxide and plutonium oxide particles