Methods of preparation of microparticles for radioactive particle tracking experiments.

Radioactive particle tracking (RPT) technique is a relatively newer technique for the characterization of flow of process materials (liquids, solids) in laboratory- and pilot-scale industrial systems. The technique uses a single particle labelled with a suitable radioisotope having similar physical properties to that of the bulk of the process material. The preparation of a representative radioactive microparticle is a challenging task in the implementation of the technique. There are no standard methods available for the preparation of radioactive microparticles. This paper discusses some of the methods of preparation of radioactive microparticles for RPT studies. A few examples of RPT applications using the prepared microparticles are also discussed.

Experimental validation of design and performance parameters of radioactive particle tracking (RPT) experimentation.

In recent years, radioactive particle tracking (RPT) has emerged as a powerful noninvasive technique for characterization and visualization of flow in opaque multiphase flow reactors. This technique has been applied to a variety of multiphase flow reactors largely based on the theoretical framework for optimal design and performance parameters. No systematic evaluation and validation of the design and performance parameters of the RPT technique has been reported in the literature thus far. Consequently, the theoretical framework for the design of RPT experiments has had limited scalability and application to a wide variety of flow systems. Thus far, design of a "good" RPT experiment continues to be an art, no matter how much the richness of flow of information that the experimental method brings. The present work reports systematic experimental evaluation of design parameters for an optimal RPT experiment and validation of the theoretical results reported in literature. The experiments were performed in a carefully designed setup in which precise positioning of the tracer particle was made possible. The experiments assess the effect of various parameters on the performance of the RPT experiment, such as the choice of radioactive isotope, activity, gamma-ray energy, size of the detector, and relative positioning of detectors. Finally, a set of recommendations based on experimental work are provided to "optimally" perform the RPT experiment in any single or multiphase reactor.