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论文类型：期刊论文

发表时间：2018-07-01

发表刊物：CONTRIBUTIONS TO PLASMA PHYSICS

收录刊物：SCIE、CPCI-S

卷号：58

期号：6-8,SI

页面范围：725-731

ISSN号：0863-1042

关键字：closure; detachment; divertor; SOLPS

摘要：SOLPS modelling has shown that divertor plasma detachment occurs at a lower upstream separatrix density in the more closed DIII-D upper divertor than the open lower divertor, demonstrating the utility of the divertor closure in widening the range of acceptable densities for adequate heat handling. To achieve reduced heat flux and erosion at the plasma-facing components, future devices will need to operate in at least partially detached divertor conditions . Two-dimensional fluid plasma models coupled to Monte Carlo neutral transport simulations, such as SOLPS, have been widely used to predict the onset of detachment. In modelling the DIII-D discharges, the cross-field transport coefficients are constrained to reproduce the experimental upstream profiles. The closed divertor has been modelled with the same input parameters of the open divertor, allowing a direct comparison of the target conditions in both geometries. SOLPS simulations indicate that a higher molecular density correlates strongly with lower electron temperatures. The increased closure of the upper divertor improves the trapping of neutrals, thereby reducing the power density deposited at the target and facilitating detachment, in agreement with experimental observations.