Multiple-particle tracking using the Birmingham positron camera

The Birmingham positron camera for tracking positron-emitting particles has been successfully used in a wide range of fundamental researches and industrial applications. The technique was originally developed to track a single positron-emitting tracer particle. However, tracking multiple particles would provide more information on the physical processes taking place in a system. In this paper, a new method that is able to track more than one particle is presented. The accurate spatial locations of multiple tracers are calculated by taking account of the radioactivity concentration of each tracer and by discarding corrupted y-ray trajectories. The potential applications of the multiple-particle tracking technique are illustrated through an example by tracking two moving particles in a fluidised bed