关键词: 托卡马克等离子体；充气弹丸；数值模拟；剖面演化 

Abstract: In order to improve the charging depth and efficiency of pellets in HL-2A tokamak, an original encapsuled pellet injection fueling was recently developed. Neglecting the ablation process of the non-fuel cladding of the encapsuled pellet, the transport characteristics of the new encapsuled pellet deposited at the position of radial normalized magnetic flux equaling to 0.9 and the self-consistent interaction with the background plasma are simulated in two dimensions with Trans-neut code under HL-2A tokamak configuration. The evolutions of charging particles and background plasma profile are given. The results show that deuterium ions deposit and peak in the radial inside of feeding position, and the core density increases continually under the radial diffusion. The regions of ion temperature and electron temperature reduction at fueling position expand continually during the fueling. The evolution of electron temperature profile in poloidal direction is faster than that of ion temperature profile. The normalized molecular density and radial distribution width at feeding position decrease first and then increase, which is negatively correlated with that of the molecular decomposition at the feeding place.

Key words: Tokamak plasma, Encapsuled pellet, Numerical simulation, Profile evolution