Interatomic Coulombic Decay of clusters upon electron impact

原子间库仑衰变（ICD）是光子或高能粒子与团簇相互作用中的一个重要现象。ICD表示簇中单个电子空位的弛豫机制。电子能量随后可在连续体中转化为正离子和电子的动能。与此同时，利用光电离进行了大量的实验研究，但对电子诱导的ICD还没有系统的研究。我们将在这里研究ICD是否通过内部（价）壳激发或电子冲击电离在团簇中诱导。本项目研究的另一个过程将是原子间库伦电子捕获（ICEC）。在这个反应中，由于电子捕获而沉积在团簇原子上的多余能量，通过从团簇中相邻原子上移走一个电子而释放出来。虽然关于这一过程的详细理论已经存在，但实验验证仍然是迫切需要的。此外，我们将研究掺杂氦液滴中导致掺杂剂顺序电离的能量收集反应。本研究将在电子碰撞物理学中具有重要意义，因为它将阐明物质中电子诱导反应的新基本途径。

Interatomic Coulombic Decay (ICD) was discovered to be an important phenomenon in the interaction of photons or energetic alpha-particles with clusters. ICD represents in clusters a relaxation mechanism of a single electronic vacancy. Electronic energy may subsequently be transferred into kinetic energy of positive ions and an electron in the continuum. While a plethora of experimental studies using photo-ionization has been carried out in the meantime, no systematic investigations on electron induced ICD exist. We will investigate here if ICD is induced in clusters via inner (valence) shell excitation or ionization by electron impact. Another process studied in this project will be Interatomic Coulombic Electron Capture (ICEC). In this reaction the excess energy deposited in an atom of a cluster by electron capture is released by removal of an electron from a neighbour in the cluster. While detailed theory on this process exists, the experimental verification is eagerly awaited. Moreover, we will study energy harvesting reactions in doped helium droplets which lead to sequential ionization of dopants. The present studies will have strong implications in electron collision physics since new fundamental pathways of electron induced reactions in matter will be elucidated.