Electron impact vibrational excitation in plasmas

扩散等离子体中的电子对分子的振动激发，例如在彗星彗发中发现的或用于工业蚀刻的电子，是一个关键但知之甚少的过程。激发的振动态可以发射光子，产生可观察到的信号发射，或者成为进一步过程的垫脚石，例如通过进一步的电子碰撞进行解离。振动激发截面很难测量，即使是从振动基态的激发和激发态基本上无法测量。该提案旨在研究自然界中关键分子（如水）和蚀刻等离子体（如NF，NF 2和NF 3）的振动激发。本研究将通过开发英国分子R-矩阵代码（UKRMol）进行，该代码是在各种EPSRC赠款下开发的，并构成Quantemol有限公司分发的Quantemol-N专家系统的基础。这两个代码已被用于研究电子碰撞激发的重要性，无论是纯物理研究（如电子碰撞旋转激发）和等离子体物理（如电子碰撞解离和电离）。到目前为止，振动激发只研究了特殊情况下的共振激发的双原子分子使用一个独立的代码和不可扩展的程序。

The vibrational excitation of molecules by electrons in diffuse plasma, such as those found in cometary coma or used in industrial etching, is a key but poorly understood process. Excited vibrational states can either emit photons giving rise to tell-tale observable signature emissions or be a stepping-stone to further processes such as dissociation via further electron impacts. Vibrational excitation cross sections are hard to measure even for excitations from the vibrational ground state and essentially unmeasured for excited states. The proposal is to study vibrational excitation for key molecules naturally (such as water) and etching plasmas (such as NF, NF2 and NF3). This study will be performed by developing the UK Molecular R-matrix code (UKRMol) which were developed under various EPSRC grants and forms the basis of the Quantemol-N expert system distributed by Quantemol Ltd. Both these codes have been used to study electron collisional excitations of importance both for pure physics investigations (eg electron impact rotational excitation) and plasma physics (eg electron impact dissociation and ionisation). Thus far vibrational excitation has only been studied for the special case of resonant excitation of diatomic molecules using a standalone code and a non-extendable procedure.