Molecular dynamics simulation of tungsten surface sputtering under low–energy neon irradiation for radiative divertor scenarios

• Molecular dynamics simulations clarify Ne–W sputtering mechanisms in the 30–200 eV regime. • Sputtering yields show strong dependence on surface orientation and incidence angle behavior. • Cumulative implantation induces Ne clustering, surface roughening, and reduced sputtering yields. • Findings provide microscopic insight and quantitative source terms for boundary plasma modeling. Neon (Ne) is a key candidate impurity for radiative divertor operation in tokamaks, aiming to reduce the thermal load on the divertor targets. However, its injection can simultaneously enhance tungsten surface erosion. In this work, molecular dynamics simulations are employed to investigate the sputtering behavior of tungsten under Ne irradiation in the energy range of 30–200 eV. The effects of incident energy, crystallographic orientation, and incidence angle are systematically analyzed, and the evolution of surface morphology under cumulative bombardment is examined. The results indicate that the sputtering yield increases significantly with incident energy, with the (110) surface exhibiting the highest yield due to its high atomic density and shallow Ne implantation depth. Sputtering yields are further enhanced at specific oblique incidence angles due to more efficient momentum transfer to surface atoms. The angular and energy distributions of sputtered atoms show that low–energy sputtering is more sensitive to surface orientation. Under cumulative injection, Ne retention increases and saturates with fluence, while surface damage strongly depends on the irradiation energy and fluence. Furthermore, the growth of surface roughness leads to a reduction in sputtering yield. These findings provide microscopic insight into impurity–tungsten interactions in fusion devices and offer quantitative input for boundary plasma modeling and divertor lifetime assessment.