Development and implementation of Divertor Fast Particles Injection for EAST tokamak

Abstract

The divertor is the main device in the tokamak that is subjected to heat loads, excessive high heat flux could cause damage to the divertor target. Divertor heat flux control is very important for magnetically confined fusion devices. As a method for divertor heat flux control, the Divertor Fast Particles Injection (DFPI) is successfully developed and implemented on the Experimental Advanced Superconducting Tokamak (EAST). The components of DFPI are a high-pressure gas source (0.6–1 MPa), a pulse solenoid valve, a nozzle and the pipeline etc. Compared with the Supersonic Molecular Beam Injection (SMBI) particle injection from midplane, the particles injected by DFPI are more difficult to enter the plasma core and have less impact on the performance of the core plasma; Compared with the gas puffing (GP) particle injection from the divertor, the particles injected by DFPI can enter the divertor area faster, the delay time of DFPI is about 25 ms. The successful implementation of DFPI provides an important tool for divertor heat flux control on EAST.