First results are reported from the 3D Monte Carlo far-SOL impurity transport code 3DLIM. Tungsten deposition profiles measured on a Collector Probe (CP) located in the far-SOL near the outer midplane, OMP, during W tracer experiments in DIII-D are reproduced by 3DLIM. Radial deposition profiles are replicated showing the effect that a decrease in connection length from the CP to the nearest wall contact point has on impurity transport to the probe, as well as the effect of assuming purely diffusive vs convective radial transport. For purely diffusive radial transport, a diffusion coefficient of 10 m²/s best reproduces deposition patterns on both sides of the CP, but for purely convective radial transport a speed of 125 m/s is shown to have better agreement with the ITF deposition profile. Deposition profiles show peaking in W content along the length of the CP edges that is also reproduced in 3DLIM, but only when assuming a convection-dominated SOL plasma parallel transport prescription for the background plasma. The degree of the peaking is shown to be a secondary indicator of the effective location of the W source in the near-SOL OMP relative to the far-SOL (near/far from the separatrix). Identifying the location of the effective source provides insight into near-SOL impurity dynamics, including the existence and location of impurity accumulation near the OMP separatrix. Such accumulation typically occurs in SOLPS and other edge code modeling, but has hitherto been difficult to confirm experimentally. The impurity density at the edge is the boundary condition for impurity levels in the confined plasma.

从3D蒙特卡罗远SOL杂质迁移代码3DLIM报告了初步结果。3DLIM复制了在DIII-D中的W示踪剂实验期间，在远SOL靠近外中平面OMP的集电极探针​​（CP）上测得的钨沉积曲线。复制了径向沉积轮廓，显示了从CP到最近的壁接触点的连接长度的减小对杂质向探针的传输的影响，以及假设纯扩散对流径向对流的影响。对于纯扩散径向传输，扩散系数为10 m ²/ s最佳地再现了CP两侧的沉积模式，但是对于纯对流径向传输，显示125 m / s的速度与ITF沉积曲线具有更好的一致性。沉积曲线显示出沿CP边缘的长度W含量达到峰值，这也在3DLIM中得以再现，但仅在假设对流占优势的SOL等离子体平行传输处方用于背景等离子体的情况下。峰化程度显示为W源在近SOL OMP中相对于远SOL（距分离线近/远）的有效位置的辅助指标。确定有效源的位置可洞悉近SOL杂质动力学，包括OMP分离层附近杂质积累的存在和位置。这种累积通常发生在SOLPS和其他边缘代码建模中，但是迄今为止很难通过实验进行确认。边缘处的杂质密度是受限等离子体中杂质水平的边界条件。