Speaker
Description
The tokamak divertor is subjected to huge heat load, including both the transient heat load due to the edge localized modes (ELMs) and steady-state heat load in between ELMs. Exploring the edge plasma solution compatible with the high-performance plasma is critical for the fusion reactors. Numerical simulations are indispensable for both understanding the edge plasma physics and predicting the edge plasma behavior. However, the cross-field transport coefficients adopted in the transport codes such as SOLPS-ITER, UEDGE, EDGE2D-EIRENE and SOLEDGE2D-EIRENE are usually given empirically or by fitting experiments. On the other hand, although the turbulent cross-field transport of the edge plasma can be simulated by lots of turbulence codes such as BOUT++ and JOREK, it is hard to achieve a self-consistent simulation of the edge plasma transport due to the large gap between the turbulence and transport time scales. One effective way to realize a self-consistent edge plasma simulation is the coupling simulation by the transport and turbulence codes [1, 2].
For the purpose to implement the self-consistent coupling simulation of the edge plasma automatically and efficiently, a simulation framework called EPCS (Edge Plasma Coupling Simulation) is developed recently [3]. At the present stage, BOUT++ [4] is chosen as the turbulence code and SOLPS-ITER [5] as the transport code. To simulate multiple full ELM cycles, a time-dependent coupling simulation workflow is developed [6]. Based on the time-dependent workflow, the simulations are conducted for the grassy ELM experiment [7] and the neon-seeding experiment (where both detachment and grass ELM regime are achieved) [8] in EAST. For both cases, multiple ELM cycles are successfully simulated, which have the ELM frequencies consistent with the experiments. Especially, the influence due to the injection of neon impurities on the divertor detachment and the ELM size and frequencies is qualitatively reproduced. Further analysis of the detailed mechanisms will be reported in the conference.
References
[1] T.D. Rognlien, et al., Contrib. Plasma Phys. 44 (2004) 188–193.
[2] D.R. Zhang et al., Nucl. Fusion 60 (2020) 106015.
[3] T.Y. Liu et al., Plasma Phys. Control. Fusion 67 (2025) 055004.
[4] X.Q. Xu et al., Phys. Plasmas 7 (2000) 1951–1958.
[5] S. Wiesen et al., J. Nucl. Mater. 463 (2015) 480–484.
[6] T.Y. Liu et al., submitted to Plasma Phys. Control. Fusion.
[7] G.S. Xu et al., Phys. Rev. Lett. 122 (2019) 255001.
[8] Q.Q. Yang et al., Nucl. Fusion 60 (2020) 076012.