Time-dependent simulation of erosion and migration of tungsten during ELMs with GITR*

The 3D Monte Carlo impurity transport code, GITR [1], has previously been used to solve the steady state net erosion profiles in linear devices and tokamaks [2]. This model has assumed a constant plasma background, thereby resulting in a persistent source of surface material erosion due to the plasma species.

 

Edge-localized modes (ELMs) result in periodic transients that introduce higher densities and fluxes to the materials connected to the edge plasma along magnetic field lines. This causes increased sputtered material flux but can also modify eroded atom behavior because of the change in local plasma parameters.

 

Several experimental methods have been used to assess erosion during intra-ELM and inter-ELM periods, including time and spatially resolved measurements, and averaging over a campaign [3]. This work aims to use simulation to characterize the driving mechanisms connecting ELMs, the redeposition rates of eroded material, and material penetration into the scrape-off layer.

[1]  T. Younkin et al., Computer Physics Communications, 264 (2021), 107885.

 

[2]  Dhyanjyoti D. Nath et al., Computer Physics Communications, Volume 292, 2023, 108861, ISSN 0010-4655, https://doi.org/10.1016/j.cpc.2023.108861.

 

[3] G.J. van Rooij et al., Journal of Nuclear Materials, Volume 438, Supplement, 2013, Pages S42-S47, ISSN 0022-3115.