The ion (T _i) and electron (T _e) temperatures at the last closed flux surface (LCFS) during density scanning discharges and in the scrape-off layer (SOL) with a constant plasma density have been measured in the J-TEXT tokamak using a retarding field analyzer and four-tip Langmuir probe, respectively. Both the LCFS T _i and T _e are found to reduce with increasing central line-averaged density (). The temperature ratio (τ = T _i/T _e) is about 2 for a low (1.5 → 2.5 10¹⁹ m⁻³), decays in a moderate (2.5 → 3.5 10¹⁹ m⁻³) and tends to unity at a high (3.5 → 4.2 10¹⁹ m⁻³). This suggests that the ions and electrons at the LCFS (even in the SOL) are thermally decoupled at low or moderate and tend to full thermal coupling in the high-density plasmas. In addition, both T _i and T _e decrease with the radius and T _e falls more steeply than T _i due to faster parallel energy loss of electrons in the SOL. In contrast, τ rises with the radius, which indicates that the ions and electrons are much more thermally decoupled in the deeper SOL.

在 J-TEXT tokamak 中测量了密度扫描放电期间最后一个闭合通量表面 (LCFS) 和具有恒定等离子体密度的刮除层 (SOL) 中的离子 ( T _i ) 和电子 ( T _e ) 温度分别使用阻滞场分析仪和四尖端朗缪尔探头。发现LCFS T _i和T _e都随着中心线平均密度 ( ) 的增加而减小。温度比（τ = Ť _我/ Ť _ë）为约2的低（1.5→2.5 10 ¹⁹米^-3），在一个温和的衰变(2.5 → 3.5 10 ¹⁹ m ^-3 ) 并且在高处趋于统一(3.5 → 4.2 10 ¹⁹ m ^-3 )。这表明 LCFS（甚至在 SOL 中）的离子和电子在低或中等热解耦，并在高密度等离子体中趋于完全热耦合。此外，由于 SOL 中电子的平行能量损失更快，T _i和T _{e 均}随半径减小，并且T _e比T _i下降得更快。相比之下，τ随半径增加，这表明离子和电子在更深的 SOL 中热解耦的程度更高。