Abstract
Abstract
To address the issues of mitigation and control of the heat loads on the divertor target, a snowflake divertor (SFD) has been proposed on the HL-2M tokamak. In this work, simulations have been performed by using SOLPS-ITER to demonstrate the advantages of SFD on HL-2M on plasma detachment and impurity screening during impurity seeding. Firstly, neon (Ne) and argon (Ar) seeding are chosen for comparison in SFD. It is found that Ar seeding significantly mitigates the in-out asymmetry compared with Ne seeding, mainly in high seeding rate cases. The impurity screening capabilities with Ar seeding are conspicuously better than that of Ne seeding. Subsequently, the SFD and standard divertor (SD) with Ar seeding are compared. The SFD achieves plasma detachment with a seeding rate of more than one order of magnitude lower and has better impurity screening capability than those of the SD. This can be explained by more substantial Ar accumulation in the private flux region near the X-point in SD. Moreover, the simulation shows that D2 puffing near the OMP can drive more Ar ions to the divertor and promote the plasma detachment and impurity screening. Finally, the effects of E × B drift on SFD are studied. It is found that with E × B drift more Ar particles accumulate in the vicinity of both inner and outer targets, especially in the far-SOL region, thus raising the far-SOL power radiation. However, the peak heat flux is mainly located near the separatrix, therefore a higher seeding rate is required to achieve detachment. Moreover, the E × B drift drives more Ar particles away from the core region. In addition, the role of molecules on the plasma momentum loss during detachment is analyzed.
Funder
National Key R&D Program of China
Fundamental Research Funds for the Central Universities
National Natural Science Foundation of China
Russian Foundation for Basic Research
Subject
Condensed Matter Physics,Nuclear and High Energy Physics
Cited by
5 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献