The centrifuge of the Pellet Launching System for JT-60SA: initial test results

• Manufacturing of the centrifuge has reached the Factory Acceptance Test stage. • Dynamic, seismic and leak tests passed. • Issues were detected during the endurance test at feedthrough temperature. Part of the Broader Approach, JT-60SA was established as satellite experiment supporting ITER and paving the way for a future fusion power plant. Its research plan calls for a powerful Pellet Launching System (PLS), capable for both particle fuelling and ELM pacing. These different tasks are achieved simultaneously by combining a pellet source for each purpose on a centrifuge. This stop cylinder type centrifuge provides dedicated pellet launch slots, which can be filled by the pellet sources controlled by a master programmable logic control (MasterPLC) system. Previously, centrifuges like those used at ASDEX Upgrade and JET were built by modifying a large turbomolecular pump and adding an acceleration arm. The advanced novel system reported here takes an approach that separates the drive from the arm. A ferrofluidic rotary motion feedthrough, capable of speeds up to 166 Hz, transfers the rotary motion from a commercial servomotor operating in the atmosphere to a rotor blade in the high vacuum. This system is designed to launch pellets with a velocity of up to 600 m/s when the centrifuge is rotating at 120 Hz. The factory acceptance test has almost been passed. After passing the endurance test, the system will be delivered to IPP Garching, followed by a commissioning phase in the pellet lab.