the dataset of Design of a centrifugal acceleration system for high velocity injection of impurity pellet into EAST tokamak

A centrifugal pellet injection system for high velocity impurity pellet injection to control ELMs and researchimpurity transport has been developed for the Experimental Advanced Superconducting Tokamak (EAST). Thesystem is composed of the dropper, the centrifugal accelerator, vacuum pumping system and the diagnostic unit.The centrifugal accelerator is designed to accelerate the pellet by the rotating arm driven by a KYKY F100turbomolecular pump with an adjusted rotating velocity from 0 to 42,300 rpm. In order to evaluate the stabilityof the rotating arm, the stress distribution of the rotating arm at different rotating velocities is analyzed by thestress field simulation, and the result shows the maximum stress of the rotating arm appears at the transitionposition between the large circular groove and the acceleration groove. By simulation analysis, it is noted thatthe arm can work steadily at 2500 rad/s (corresponding to about 398 Hz arm rotation frequency) rotating velocityand may be broken at 4000 rad/s (637 Hz). By the bench testing using the Li pellets of 1 mm diameter asinjection material, it shows the centrifugal accelerator can work steadily for a long time under the condition thatthe rotating velocity doesn’t exceed 2200 rad/s (350 Hz) and the maximum velocity of the pellet can reach 286m/s. Based on the results of simulation and bench test, the centrifugal pellet injection system was installed andthen injected Li pellets into the plasma steadily and continuously with the rotating velocity <2200 rad/s onEAST.