| High-confinement mode (H-mode) in conjunction with edge localized modes (ELMs) is a very important operation regime for a steady-state operation fusion device, since it can maintain the capability of tokamak confinement through periodically expelling impurities and energy from the core plasma. For this reason, ITER has long been foreseen to operate in this regime. However, ELMs are very difficult to control so that divertor plates are very prone to be damaged by frequent giant ELMs. Therefore, the modeling of ELMy H-mode is exceedingly significant for future steady-state operation ITER and current fusion devices. As a long-pulse advanced superconducting tokamak device, EAST has also achieved H-mode and various types of ELMs by different power injection scenarios, i.e., with LHCD, ICRH, and combined LHCD and ICRH. Meanwhile, the impacts of particle and energy fluxes during ELMy H-mode on the divertor targets were particularly studied through Langmuir Probes in EAST. Up to date, few studies have yet been conducted on modeling ELMy H-mode of EAST using the edge plasma fluid (B2.5)-neutral Monte-carlo (EIRENE) code package SOLPS, which is very important and necessary for deeper understanding and better control of ELMy H-mode. In this work, SOLPS is employed to study the ELMy H-mode discharges in EAST.Firstly, steady-state H-mode is obtained by adjusting the perpendicular radial anomalous transport coefficients (PATCs) to match with upstream profiles of experiment measurements. After PATCs of the upstream is determined, the downstream divertor region can be modeled. On the basis of H-mode simulation, the effects of drift on divertor targets power asymmetry and the power attenuation width of SOL on the peak power density to the divertor target are modeled separately, the simulation results indicate that the drift (E×B,B×▽B) is one of the main reasons for targets power asymmetry, and reducing of power damping width of the SOL will increase the peak power load on the divertor target sharply; however, due to the presences of interaction of plasma and neutral gas or radiation in divertor region, the peak power density increases inconspicuously with the reducing power damping width.Secondly, we adjust the PATCs by matching the experimental upstream radial electron density and temperature profiles under given type-III ELMy H-mode discharge conditions (shot#33266) to obtain the steady-state H-mode, and then, ELMs are modeled by periodically enhancing PATCs with the parameters, such as the repetition frequency and the energy expelled from the core plasma, taken directly from the experimental data of the given EAST discharge. The simulation shows satisfactory agreement with the experimental measurements, but largely overestimation of the target Te at the outer target during the ELMs.This is similar with the JET modeling. Besides, the in-out divertor asymmetry during the ELMs is more obvious than that during the H-mode, and the IODA is proportional to the energy expelled from the core plasma during ELMs. This result imply that there may be other reasons for IODA, such as ballooning instability. This prediction awaits future investigation. In this way, many experimentally inaccessible upstream parameters can be evaluated through the simulation; besides, this work will provide a perfect base for the further simulation of radiative divertor regimes by means of a combination of gas puffing and impurity injection to mitigate the damage from ELMs to target plates. |
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