关键词: 分子动力学, 聚变材料, 沉积率, 溅射率, 散射

Abstract:

The molecular dynamics simulations of interactions between CH₃ and tungsten materials of different temperature are carried out, based on the reactive empirical band order function to understand the possible mechanisms of C, H deposition and sputtering on the first wall in fusion device. The energy of incident CH3 particle is 200eV. The simulated results show that the deposition atoms of C and H increase with incident particle increasing, when substrate temperature is 100K the deposition of C atoms was more than others temperatures’, and when the substrate temperature is 1200K, the incident is greater than 1.510¹⁶cm^-2, the deposited C atoms is less than other substrate temperatures’ deposited C atoms. CH₃ was decomposed during CH₃ bombardment with substrate, about 9% of the CH₃ was completed decomposition; about 40% of the CH₃ was decomposited to CH₂ and H; about 23% of the CH₃ was decomposited to CH and 2H. The scattering angle of C and H atoms are mainly distributed between 5° and 85°, the distribution of scattering angle maximum of C atom was 40~50° or 50~60°, the minimum distribution of C atom at between 0 and 10° or between 80° and 90°; the energy of scattered C atoms is between 0 and 140eV, more than 98% scattering atoms is between 0 and 120eV among of them, and the average scattering energy increases with the increase of substrate temperature, from 65.5eV increased to 68.5eV, The distribution maximum of H atom was 40~50°, the minimum distribution of H atom at between 0 and 10°. Scattering energy of H atom is between 0 and 140eV, but about 70% of the scattering H atomic energy within 40eV, the average scattering energy decreases with the increase of substrate temperature, from 13.92eV decreased to 13.05eV.

Key words: Molecular dynamics, Fusion materials, Deposited rate, Sputtering rate, Scattering