Positron emission particle tracking of inclusions in cast liquid metals

A greater understanding of the PEPT process in dense materials has been achieved. PEPT is dependent upon the γ-ray attenuation between a tracer particle and the detectors of a positron camera. A lower limit for the radioactivity requirement for the positron camera used, was determined. PEPT in metal casting, was verified by recovering a particle from the location it had been tracked to during an experiment. An increase in the maximum temperature used with the process was also achieved. The effectiveness of ceramic foam filters was studied, the proportion of particles which passed through filters with pore sizes ranging from 10 to 30ppi was shown. The passage of inclusions through an open topped launder was also physically studied; A new geometry for a PEPT positron camera was specifically developed. In addition to the physical experiments a computer model was written, giving some additional insight into the behaviour of particles travelling through the launder. The model shows particles within the steady state flow of an industrial launder, into which a baffle was placed in the path of both the metal and the particles. Direct comparisons between the simulation and the physical experiment were drawn