ERO2.0 modelling of nanoscale surface morphology evolution

Abstract

Plasma–material interaction (PMI) in tokamaks determines the life-time of first-wall (FW) components. Due to PMI, FW materials are eroded and transported within the device. Erosion is strongly influenced by the original morphology of the component, due to particle redeposition on near surface structures and to the changing of impact angle distributions, which results in an alteration of the sputtering effects. The Monte-Carlo impurity transport code ERO2.0 is capable of modelling the erosion of non-trivial surface morphologies due to plasma irradiation. The surface morphology module was validated against experimental data with satisfactory agreement. In this work, we further progress in the validation of the ERO2.0 capabilities by modelling both numerically generated surfaces as well as real surfaces, generated using atomic force microscopy (AFM) measurements of reference tungsten samples. The former are used to validate ERO2.0 against one of the morphology evolution models present in literature, in order to outline the conditions for reliable code solutions. Modifications induced in AFM-generated surfaces after argon and helium plasma irradiation are compared, showing a similar post-exposure morphology, mostly dominated by surface smoothing. Finally, the ERO2.0 morphology retrieved after He plasma exposure is compared to experimentally-available scanning electron microscopy and AFM measurements of the same surface morphology exposed in the linear plasma device GyM, showing the need for further improvements of the code, while a good agreement between experimental and simulated erosion rate is observed.

Global SOLPS-ITER and ERO2.0 coupling in a linear device for the study of plasma–wall interaction in helium plasma

“…In [21], moreover, SOLPS-ITER results were also successfully compared with a simplified 0D model developed by space averaging of plasma main parameters. Erosion studies in GyM with ERO2.0 focused on the microscale surface morphology evolution of materials under plasma exposure [22]. Global erosion and migration using a suitable code for the plasma background were simulated with ERO2.0 in different tokamaks, such as JET [23], WEST [24] and ITER [25].…”

Nonlinear impact of the porous nanostructure on the net tungsten erosion in the linear plasma device PISCES-A

“…On the other hand, the three-dimensional (3D) Monte Carlo (MC) binary collision approximation simulations have been conducted to study dynamic sputtering yield by constructing a random nano-scale fuzzy surface topography [18][19][20]. Furthermore, the impacts of micro-scale rough surface morphology on the sputtering yield reduction have been studied by SURO [21] and ERO 2.0 [22,23] modellings. The empirical equation of fuzz growth rate has been established to describe the competition of W fuzz growth, annealing and erosion under transient heat pulses [24].…”