Dust particles impacting the plasma-facing material in nuclear fusion device (tokamaks) present considerable challenges to device performance and longevity [1,2]. To address these challenges, understanding the intricate dynamics of dust-wall interactions is crucial for mitigating damage and improving operational efficiency. In this study, we conduct a comprehensive investigation into these interactions at the atomic scale, employing molecular dynamics simulations that encompass a wide range of dust velocities observed in experiments. The simulations involve large-scale systems consisting of upto 200 million atoms, allowing us to elucidate the crucial roles played by impact velocity and wall material properties in shaping dust-wall interactions.

Through our analyses, we observe notable variations in the influence of dust on the wall, which are contingent upon the impact velocity and material properties. To facilitate a comprehensive understanding, we propose a categorization scheme that classifies dust-wall interactions into four distinct levels based on the resulting damage and degree of impact. Furthermore, we develop an analytical model to unravel the underlying mechanisms governing these interactions, providing valuable insights into the dynamic nature and predictive capabilities of dust-wall interactions.

The findings of this study have practical implications as they enable effective prediction and assessment of potential damage resulting from high-velocity dust impacts on plasma-facing components (PFCs). The developed analytical model serves as a valuable tool for practical applications, offering insights into the complex dynamics of dust-wall interactions. This knowledge can be utilized to optimize the design of PFCs, ensuring their resilience to withstand high-velocity dust impacts. By unraveling the dynamics and mechanisms of dust-wall interactions, this study contributes to the advancement of tokamak technology and facilitates the development of more efficient and durable fusion devices.