The formation of a substantial postdisruption runaway electron current in ASDEX Upgrade material injection experiments is determined by avalanche multiplication of a small seed population of runaway electrons. For the investigation of these scenarios, the runaway electron description of the coupled 1.5-D transport solvers ASTRA-STRAHL is amended by a fluid model describing electron runaway caused by the hot-tail mechanism. Applied in simulations of combined background plasma evolution, material injection and runaway electron generation in ASDEX Upgrade discharge #33108, both the Dreicer and hot-tail mechanism for electron runaway produce only ${\sim }$ 3 kA of runaway current. In colder plasmas with core electron temperatures $T_\textrm {e,c}$ below 9 keV, the postdisruption runaway current is predicted to be insensitive to the initial temperature, in agreement with experimental observations. Yet in hotter plasmas with $T_\textrm {e,c}$ above 10 keV, hot-tail runaway can be increased by up to an order of magnitude, contributing considerably to the total postdisruption runaway current. In ASDEX Upgrade high-temperature runaway experiments, however, no runaway current is observed at the end of the disruption, despite favourable conditions for both primary and secondary runaway.

在ASDEX升级材料注入实验中，大的破裂后失控电子电流的形成是由少量失控电子的种子雪崩倍增来确定的。为了研究这些情况，通过描述由热尾机制引起的电子失控的流体模型，对耦合的1.5D输运求解器ASTRA-STRAHL的失控电子描述进行了修正。在ASDEX升级版＃33108的组合背景等离子体演化，材料注入和电子失控产生的模拟中应用，Dreicer和电子热失控的热尾机制均仅产生$ {\ sim} $ 3 kA失控电流。在具有核心电子温度的较冷等离子体中$ T_ \ textrm {e，c} $低于9 keV，与实验观察一致，预计破裂后失控电流对初始温度不敏感。然而，在$ T_textrm {e，c} $高于10 keV的较热等离子体中，热尾失控可以增加多达一个数量级，从而极大地贡献了破裂后的总失控电流。但是，在ASDEX升级版高温失控实验中，尽管一次和二次失控都具有有利条件，但在干扰结束时未观察到失控电流。