Overview of JET Mark II A Divertor Performance in ITER-Relevant Modes of Operation

摘要

Over the last five years, the JET divertor programme has evaluated a series of different divertor geometries with increased closure to recycling neutrals. The goal is to establish combined divertor and core plasma performance acceptable for a reactor. To that end, it is necessary to combine acceptable core confinement, impurity content and density with a first wall power loading which does not overly limit component lifetimes. In addition, such an operation point must have a helium exhaust rate such that the reactor core would not be poisoned by ash. Two different lines of experiment have been followed: Non-seeded operation with large, separate ELMs, low impurity content and good confinement; and impurity seeded operation with high radiant losses and low divertor power loading. The results of these experiments are summarised and the implications for ITER discussed.