Research on the penetration characteristics of three refuelling methods on HL-1M

In plasma physics experiments of HL-1M tokamak, three refuelling methods (gas puffing, pellet and supersonic molecular beam (SMB) injection) were used. The penetration characteristics and the average speed of the pellet and molecular beam were analysed and estimated by means of contour plots of H α emissivity distribution. On HL-1M tokamak, the penetration depth of the pellet was up to 0.26 m, and the average speed of the pellet inside the plasma was less than that outside the plasma. The SMB was injected into the plasma from the low-field side and its average speed was more than 1 km s -1 .