Thermal-Hydraulic Aspects of an Extruder for Tracer-Encapsulated Cryogenic Pellet: A Research and Historical Perspective

Impurity behavior is investigated in the form of a single or multispecies pellet in a variety of fusion devices like Stellarator TJ-II, Large Helical Device, Experimental Advanced Superconducting Tokamak (EAST), etc. The impurity intentionally injected from the exterior into plasma is called a tracer impurity. The tracer can be used to trace the fluid path. This study aims to provide impurity elements used in polymer and fusion research by different researchers as well as present the progress of eminent activities with recent progress. The effects on plasma performance due to impurity injection are discussed. The impurity behavior in the plasma core is comprehensively investigated by the researchers, but their works are very limited in the cryogenic environment. As a substitute to this way, extrusion of a pellet made from a mixture of solid hydrogen and tracer element can be useful for fueling the fusion machine. Some of the mathematical models and equations assist to determine the various parameters in extrusion of the tracer mixed pellet. Investigation of the behavior of an impurity in hydrogen ice extrusion from a twin-screw extruder is crucial with respect to cryogenic restrictions.