Atomistic modeling of diffusion coefficient in fusion reactor first wall material tungsten

• Self-diffusion coefficients of fusion reactor material tungsten have been analyzed.
• Dipole interaction model is introduced to analyze diffusion in the magnetic field.
• Tungsten diffusion activation energy increases in the strong uniform magnetic field.
• The strong uniform magnetic field limits the diffusion coefficient of tungsten.

Tungsten is remarkable for its robustness, especially it has the highest melting point of all the non–alloyed metals. Metallic material tungsten and tungsten alloys have been widely used in aerospace, weapon, nuclear industries and fusion reactor. Tungsten is expected to be the fusion reactor first wall material for this reason. In this paper, self-diffusion coefficients of metallic material tungsten have been investigated via molecular dynamics simulation method using the modified embedded atom potential model. Diffusion activation energy of tungsten can be gotten according to Arrhenius relation between the self-diffusion coefficients simulation results and temperatures. The dipole interaction model is introduced to analyze metallic material tungsten self-diffusion process in a uniform magnetic field. The strong magnetic field increases diffusion activation energy by 34.52% and limits self-diffusion coefficient by 1.15% in 2 T uniform magnetic field.