Runaway electron modelling efforts are motivated by the risk these energetic particles pose to large fusion devices. The sophisticated kinetic models can capture most features of the runaway electron generation but have high computational costs, which can be avoided by using computationally cheaper reduced kinetic codes. This paper compares the reduced kinetic and kinetic models to determine when the former solvers, based on analytical calculations assuming quasi-stationarity, can be used. The Dreicer generation rate is calculated by two different solvers in parallel in a workflow developed in the European integrated modelling framework, and this is complemented by calculations of a third code that is not yet integrated into the framework. Runaway Fluid, a reduced kinetic code, NORSE, a kinetic code using non-linear collision operator, and DREAM, a linearized Fokker–Planck solver, are used to investigate the effect of a dynamic change in the electric field for different plasma scenarios spanning across the whole tokamak-relevant range. We find that on time scales shorter than or comparable to the electron–electron collision time at the critical velocity for runaway electron generation, kinetic effects not captured by reduced kinetic models play an important role. This characteristic time scale is easy to calculate and can reliably be used to determine whether there is a need for kinetic modelling or cheaper reduced kinetic codes are expected to deliver sufficiently accurate results. This criterion can be automated, and thus it can be of great benefit for the comprehensive self-consistent modelling frameworks that are attempting to simulate complex events such as tokamak start-up or disruptions.

失控电子建模工作的动机是这些高能粒子对大型聚变装置造成的风险。复杂的动力学模型可以捕获失控电子生成的大部分特征，但计算成本很高，这可以通过使用计算成本较低的简化动力学代码来避免。本文比较了简化的动力学模型和动力学模型，以确定何时可以使用基于假设准平稳性的分析计算的以前的求解器。Dreicer 生成率由两个不同的求解器在欧洲集成建模框架中开发的工作流中并行计算，并辅以尚未集成到框架中的第三个代码的计算。Runaway Fluid，一种简化的动力学代码，NORSE，一种使用非线性碰撞算子的动力学代码，以及 DREAM，线性化福克-普朗克求解器用于研究电场动态变化对跨越整个托卡马克相关范围的不同等离子体场景的影响。我们发现，在产生失控电子的临界速度下，在比电子-电子碰撞时间更短或与之相当的时间尺度上，简化动力学模型没有捕捉到的动力学效应起着重要作用。这种特征时间尺度易于计算，并且可以可靠地用于确定是否需要动力学建模或更便宜的简化动力学代码来提​​供足够准确的结果。这个标准可以自动化，