Diagnostics and Operation of the Pellets at Columbia Test Stand

Among various plasma disruption mitigation techniques, massive material injection with cryogenic pellets has emerged as a leading method for controlling plasma behavior. Understanding the ablation of cryogenic pellets enables well-tuned mitigation. The Pellets at Columbia (PAC) test stand intends to provide direct ablation data under controlled high-energy conditions via an electron beam.

Several PAC measurement systems and methods have been implemented that are required for effective pellet injection and ablation study. Such diagnostic methods include the microwave cavities, fast camera/lighting, pellet tracking code, and rocket effect pellet deflection angle analysis. Together, these diagnostics play an essential role in the investigation of cryogenic pellet injection, advancing the development of pellet technology. This poster will present the current status of these diagnostic systems.