To improve the properties of castings, a new technique to observe the fluid flow and study the motion of oxygen-bearing inclusions has been developed. This new technique, Positron Emission Particle Tracking (PEPT), enabled a single radioactive tracer particle, moving inside a liquid metal casting, to be tracked with an accuracy of some millimeters, depending on the properties of the liquid metal and the mold. These novel experiments give promising results to observe the liquid metal flow and locate the tracked particle in a casting. Experiments have shown that various particle sizes (200 to 600 μm presented here) can be used to observe the liquid metal flow, if the particle has sufficiently initial radioactivity. Different sizes of particles are considered and their radioactivity compared in terms of their usefulness for tracking in flowing liquid aluminum according to the specific surface area.

中文翻译：

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通过正电子发射跟踪研究液态金属流动

为了提高铸件的性能，开发了一种观察流体流动和研究含氧夹杂物运动的新技术。这种新技术，即正电子发射粒子跟踪 (PEPT)，能够根据液态金属和模具的特性，以几毫米的精度跟踪在液态金属铸件内部移动的单个放射性示踪粒子。这些新颖的实验为观察液态金属流动和定位铸件中的跟踪粒子提供了有希望的结果。实验表明，如果颗粒具有足够的初始放射性，则可以使用各种粒径（此处显示的 200 至 600 μm）来观察液态金属流动。