Designed, fabricated, and assembled a modular high vacuum feedthrough diagnostic system. Interfaced with scientists to create a modular diagnostic system to aid in analyzing characteristics of a magnetized plasma. The system allows for a multitude of diagnostic probes to be used in a high vacuum chamber. The design utilizes a sliding differential seal to make linear positioning and rotational movement possible while maintaining a high vacuum in the main chamber. The head/effector has a custom designed electrical connector that allows different probes to be installed quickly and easily. The design is completely self-contained and the wired connections are routed through cable chain to the breakout BNC connectors in the back plate. Ultimately, the design’s modularity has proven extremely useful in testing different characteristics of the magnetized plasma.