The core transport code, JETTO, coupled to the neutral Monte Carlo code, EIRENE, has been used to examine the sensitivity of the JET H-mode pedestal to the neutral flux crossing the separatrix. The Neutral Penetration Model (NPM) [Groebner et. al., Physics of Plasmas 9, 2134 (2002)] predicts the width of the density pedestal along the neutral path to scale with the inverse of its height: $1/n_{e,\mathit{ped}}$. By keeping the same physics assumptions in the NPM, and setting the deuterium atoms to cross the separatrix at the same location as the synthetic diagnostic line of sight (i.e. at the outer mid-plane, OMP), we were able to reproduce this scaling in JETTO-EIRENE. However, when the atoms were set to cross the separatrix at the X-point (more consistent with EDGE2D-EIRENE simulations of JET H-modes), the density width at the OMP was found to be much more sensitive to the pedestal height (approximately proportional to $1/n_{e,\mathit{ped}}^2$). This is attributed to a radial variation in the poloidal flux expansion from OMP to X-point, over the range of ionisation mean free path lengths explored in the scan. Accounting for this variation allowed the expected scaling at the OMP to be recovered. Implications are discussed for experimental comparisons to the NPM and its application to pedestal prediction models.

核心传输代码 JETTO 与中性蒙特卡罗代码 EIRENE 耦合，已用于检查 JET H 模式基座对穿过分界线的中性通量的敏感性。中性渗透模型 (NPM) [Groebner et. al., Physics of Plasmas 9, 2134 (2002)] 预测密度基座沿中性路径的宽度以与其高度的倒数成比例：$1/n_{\mathrm{电子},\mathit{佩德}}$. 通过在 NPM 中保持相同的物理假设，并将氘原子设置为在与合成诊断视线相同的位置（即在外中平面，OMP）处穿过分界线，我们能够在JETTO-EIRENE。然而，当原子被设置为在 X 点穿过分界线时（与 JET H 模式的 EDGE2D-EIRENE 模拟更一致），发现 OMP 处的密度宽度对基座高度更敏感（大约正比于$1/n_{\mathrm{电子},\mathit{佩德}}^2$）。这归因于从 OMP 到 X 点的极向通量扩展在扫描中探索的电离平均自由程长度范围内的径向变化。考虑到这种变化，可以恢复 OMP 的预期缩放。讨论了与 NPM 的实验比较及其在基座预测模型中的应用的含义。