Incorporating molecular and impurity effects into kinetic parallel electron transport modelling of scrape-off layer detachment

该项目侧重于详细建模动力学，平行电子传输沿磁场线与原子和分子物理发生在分流器附近的相互作用。目标是了解非局部效应（从岩心边缘流向分流器的无碰撞电子）如何影响分离，特别是在不稳定驱动的岩心爆发（即elm）期间，分离对瞬态载荷的响应。该项目将建立在SOL-KiT代码的基础上，由Stefan Mijin（帝国博士奖学金学生，三年级）在Kingham博士（帝国理工学院）和Militello博士（CCFE）的监督下开发。目前，SOL-KiT隐式地求解电子的Vlasov-Fokker-Planck方程和沿场线的单个离子的流体方程。它包括中性原子的碰撞辐射模型。为了恰当地考虑脱离，需要额外的物理效应；分子物理（即计算D2+）和杂质离子种类。SOL-KiT将升级以包括这些。动力学模型也将用于离子和潜在的中性物质。博士生将使用这个增强的代码来研究动力学效应如何影响分离过程，稳态分离的参数空间及其对elm的灵敏度和响应。将获得合成光谱，为实验分析和设计提供信息。

This project focuses on detailed modelling of the interplay of kinetic, parallel electron transport along magnetic fields lines with atomic & molecular physics occurring near the divertor. The goal is to understand how detachment is affected by non-local effects (collisionless electrons streaming from the core-edge to the divertor), especially its response to transient loading during instability driven outbursts from the core (i.e. ELMs). The project will build upon the SOL-KiT code, developed by Stefan Mijin (Imperial PhD Scholarship student, in year 3) under the supervision of Dr Kingham (Imperial) & Dr Militello (CCFE). Currently, SOL-KiT implicitly solves the Vlasov-Fokker-Planck equation for electrons and fluid equations for a single ion species along a field-line. It includes a collisional-radiative model for neutral atoms.In order to properly consider detachment, extra physical effects are required; molecular physics (i.e. accounting for D2+) and impurity ion species. SOL-KiT will be upgraded to include these. Kinetic modelling will be used for ions and potentially neutrals too. The PhD student will use this enhanced code to investigate how kinetic effects influence the process of detachment, the parameter space for steady state detachment and its sensitivity and response to ELMs. Synthetic spectra will be obtained, to inform analysis and design of experiments.