Midplane separatrix density is a crucial parameter in tokamaks since it strongly impacts divertor conditions. Scaling midplane separatrix density, n_{e, SEP}, and pedestal density, n_{e, PED}, as function of engineering parameters such as auxiliary heating P_injected, toroidal magnetic field B_T, and plasma poloidal current I_p are relevant to observe the effect of tuning these parameters on, for example, quality of confinement and divertor regime governed by n_{e, PED} and n_{e, SEP}, respectively. Thus, a dataset of JET H‐mode pulses performed with Iter like wall (ILW) has been analysed. Midplane density data are collected from an HRTS (high‐resolution Thomson scattering) diagnostic and n_{e, SEP} is determined using the power balance method. Parallel heat flux model is chosen using transport code SOLEDGE2D (S2D) applying power balance method over a simulated n_{e, SEP} and T_{e, SEP} profiles to obtain separatrix positions. The parameters are averaged over time windows with order of (85–185 ms) and the magnetic configuration has been fixed to avoid divertor geometrical effect on n_{e, SEP} determination, configuration chosen is corner–corner. A ratio between separatrix density and pedestal density at outer midplane ranges between 0.3 and 0.7 on the data set. A scaling law of n_{e, SEP}/n_{e, PED} is obtained as function of P_injected, B_T, and I_P.

中文翻译：

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JET中平面分离密度与工程参数的关系研究

在托卡马克中，中平面分离密度是一个关键参数，因为它会强烈影响偏滤条件。根据工程参数（例如_注入的辅助加热P，环形磁场B _T和等离子极向电流I _p）的变化，缩放中平面分离线密度n _e，SEP和基座密度n _e，PED的函数与观察磁滞效应有关。在例如由n _e，PED和n _{e，SEP控制}的约束质量和分流器范围上调整这些参数， 分别。因此，已经分析了使用Iter like wall（ILW）执行的JET H模式脉冲的数据集。平面密度数据从HRTS（高分辨率汤姆逊散射）诊断，并收集Ñ _ë，SEP被使用的功率平衡方法测定。使用传输码SOLEDGE2D（S2D）施加的功率平衡方法在模拟被选择平行热通量模型Ñ _ë，SEP和Ť _ë，SEP型材以获得分界面位置。的参数在时间上平均窗用的（85-185顺序 毫秒）和磁性构型已被固定，以避免对偏滤器几何效应Ñ _ë，SEP确定，选择的配置是角落。在数据集上，外中平面处的分离密度与基座密度之比在0.3到0.7之间。获得n _e，SEP / n _e，PED的比例定律，作为P_注入，B _T和I _P的函数。