The JET exploitation plan foresees D–T operations in 2020 (DTE2). With respect to the first D–T campaign in 1997 (DTE1), when JET was equipped with a carbon wall, the experiments will be conducted in presence of a beryllium–tungsten ITER-like wall and will benefit from an extended and improved set of diagnostics and higher additional heating power (32 MW neutral beam injection + 8 MW ion cyclotron resonance heating). There are several challenges presented by operations with the new wall: a general deterioration of the pedestal confinement; the risk of heavy impurity accumulation in the core, which, if not controlled, can cause the radiative collapse of the discharge; the requirement to protect the divertor from excessive heat loads, which may damage it permanently. Therefore, an intense activity of scenario development has been undertaken at JET during the last three years to overcome these difficulties and prepare the plasmas needed to demonstrate stationary high fusion performance and clear alpha particle effects. The paper describes the status and main achievements of this scenario development activity, both from an operational and plasma physics point of view.
JET的利用计划预见到在2020年进行D–T运行（DTE2）。与1997年的首次D–T活动（DTE1）相比，当时JET配备的是碳壁，而此次实验将在具有铍–钨ITER类似壁的条件下进行，并将受益于扩展和改进的诊断系统以及更高的辅助加热功率（32 MW中性束注入+8 MW离子回旋共振加热）。新壁条件下的运行带来了若干挑战：台基约束的整体退化；芯部重杂质积累的风险，若不加控制可能导致等离子体辐射崩塌；以及保护偏滤器免受过高热负荷的要求，否则可能造成永久性损伤。因此，过去三年中JET开展了一项密集的情景开发活动，以克服这些困难并制备所需的等离子体，从而演示稳态高性能聚变和清晰的阿尔法粒子效应。本文从运行和等离子体物理两个角度描述了这一情景开发活动的现状及主要成果。