High-density discharges in JT-60U have been analysed with the aim of establishing a mechanism for the H-mode density limit (DL). The data support the view that the density behaviour in the H-mode is mainly affected by confinement, with the hard limit on the H-mode density being imposed by the H-L transition. Analysis of highly radiating NBI-heated plasmas with MARFE and detachment has enabled one to discriminate between detachment and the H-L transition as mechanisms for the H-mode DL. Although strong detachment is observed near the H-L transition in JT-60U, by itself it was found to impose no limit on the density rise.
高密度放电在JT-60U中已被分析，旨在建立H模密度极限（DL）的机制。数据支持以下观点：H模中的密度行为主要受约束影响，而H模密度极限的硬性限制则由H-L转换施加。对具有MARFE和脱离的高辐射NBI加热等离子体的分析，使得能够区分脱离与H-L转换作为H模密度极限的机制。尽管在JT-60U中观察到强脱离接近H-L转换，但发现其本身并未对密度上升施加限制。