A PEPT algorithm for predefined positions of radioisotopes relative to the tracer particle.

PEPT has been used to study the flow of material in a wide range of industrial systems. Usually, by invoking the ergodic assumption for the behaviour of the flow field, a single tracer, tracked over a sufficiently long period, can be used to characterize the velocity field of a steady state system. Starting with a known distribution of positron-emitting-radioisotope within the tracer particle, an optimised Positron Emission Particle Tracking (PEPT) algorithm for determining the centroid of the tracer is presented. A simple geometric constraint is iteratively employed to isolate only those lines of response passing through the tracer. The algorithmic approach for isolating the valid lines of response is presented within the context of PEPT experiments using stationary and moving tracers.