Implementation and Preliminary Analysis of single/dual-SPI based on NIMROD

Compared with massive gas injection(MGI), shattered pellet injection(SPI), as a method which is likely to apply on ITER, has advantages in deep injection and faster penetration speed. This paper introduces the NIMROD(non-Ideal MHD with Rotation, Open Discussion) code coupled with SPI module to carry out numerical simulations. Based on the SPI experiments on the J-TEXT, a set of SPI parameters are selected and scanned, including impurity amount, shattered degree and plume speed. From the results, simulations are in good agreements with experiments. Besides, the paper also achieve dual-SPI simulations which has mainly analyzed magnetic stochasticity and radiation. Though simulation results show dual-SPI may not evoke a higher MHD instabilities, it will bring different modes increasing situations. Dual-SPI will produce more radiation, advance thermal quench(TQ) and heighten current quench(CQ) rate. What's more, dual-SPI can improve radiation asymmetry apparently.