A technique for measuring interfacial area in two-component two-phase flows, based on the transmission of short-range beta or alpha particles across interfaces is proposed. One of the phases contains the radioisotope source, whereas the other contains scintillating material. For short-range particles, it was hypothesized that the number crossing interfaces would originate from very thin layers that are immediately adjacent, and therefore, would lead to a scintillation rate directly proportional to the interfacial area and radioisotope concentration. A series of experiments to check this hypothesis was done with solid-liquid and liquid-liquid systems of known interfacial area. It was found that the scintillation count rate was independent of the orientation of the interfaces and directly proportional to their area. The count rate was also essentially independent of thicknesses of the radioisotope-bearing fluid and the solid scintillating material. However, when a liquid scintillator was used the count rate was found to increase slowly with the scintillator thickness. If this problem can be resolved, it should be possible to measure interfacial area in two-phase systems by this method.
Short Range Alpha-Particles from Fluorine Bombarded with Protons
