Dedicated electron heat transport experiments have been carried out in L- and H-mode Deuterium plasmas of the JET-ILW tokamak to identify the amount of electron heat carried by electron-scale electron temperature gradient (ETG) modes. Ion cyclotron resonance heating at different positions has been used to probe the response of the electron temperature inverse gradient length R/L _Te to changes in electron heat flux q _e, while different amounts of neutral beam heating allowed to scan the ratio of ion to electron temperature T _e/T _i, which is a key parameter for the onset of ETGs. Results indicate a steepening of the normalized q _e vs R/L _Te curve above R/L _Te ∼ 8 for T _e/T _i ⩽ 1, suggestive of the ETG onset. Ion-scale gyro-kinetic (GK) simulations match the ion heat flux and the low-R/L _Te part of the q _e curve, but do not reproduce such steepening at high R/L _Te. Multi-scale GK simulations covering both ion and electron scales and including one impurity bundling light and heavy species indicate an ETG contribution only for R/L _Te values larger than the experimental ones. Sensitivity studies of such result are difficult to achieve due to limitation in numerical resources. The quasi-linear TGLF model has been used for sensitivity studies. With the same bundled impurity as the GK multi-scale, TGLF shows the q _e steepening at much larger R/L _Te values than in experiment, but when using the real mix of light impurities neglecting the heavy impurities, TGLF gets closer to the experimental results. Profile simulations with TGLF including both light and heavy impurities show over-prediction of T _e profiles and in some cases also of density, but good T _i predictions, confirming issues with the model electron stiffness for these plasmas.

已经在 J​​ET-ILW 托卡马克的 L 和 H 模式氘等离子体中进行了专门的电子热传输实验，以确定电子尺度电子温度梯度 (ETG) 模式携带的电子热量。不同位置的离子回旋共振加热已被用于探测电子温度逆梯度长度R / L _Te对电子热通量q _e变化的响应，而不同数量的中性束加热允许扫描离子与电子的比率。温度T _e / T _i，这是 ETG 开始的关键参数。结果表明归一化q _e陡峭VS - [R /大号 _碲上述曲线- [R /大号 _碲〜8 Ť _é / Ť _我⩽1，ETG的暗示发病。离子尺度陀螺动力学 (GK) 模拟与离子热通量和q _e曲线的低R / L _Te部分相匹配，但在高R / L _{Te 时}不会重现这种陡峭。多尺度 GK 模拟涵盖离子和电子尺度并包括一种杂质捆绑轻和重物质表明 ETG 贡献仅对R / L _Te 值大于实验值。由于数值资源的限制，这种结果的敏感性研究很难实现。准线性 TGLF 模型已用于敏感性研究。使用与 GK 多尺度相同的捆绑杂质，TGLF在比实验中大得多的R / L _Te值下显示q _e陡峭，但是当使用轻杂质的实际混合而忽略重杂质时，TGLF 更接近实验结果。包含轻杂质和重杂质的 TGLF 剖面模拟显示对T _e剖面的过度预测，在某些情况下也对密度进行了过度预测，但T _i良好 预测，确认了这些等离子体模型电子刚度的问题。