Detecting Interatomic and Intermolecular Coulombic Decay in clusters by fluorescence

原子间库仑衰变（ICD）是弱束缚系统中的一种无辐射跃迁，是低动能电子的有效来源。到目前为止，ICD过程只能在超高真空中通过使用电子和/或离子谱来探测。在这里，我们建议通过检测随后发射的特征荧光辐射来研究ICD过程，这使得它们在稠密介质中的研究成为可能。计划进行三项原型研究。第一个实验将测量氖团簇上的时间和能量分辨的分散荧光，以获得均匀系统中发射辐射的特性。在第二个实验中，荧光检测的优势-初始，中间和最终状态的选择性-将被用来直接显示从一个合作伙伴的异质集群的能量传输到其他。第三个实验将把该方法应用于更复杂的目标，即H2O团簇。该项目最终可能将关于无处不在的ICD过程的实验从人工稀有气体团簇扩展到无所不在的介质，即纳米冰晶（H2O团簇）。

Interatomic coulombic decay (ICD), a radiationless transition in weakly bound systems, is an effective source for electrons of low kinetic energy. So far, the ICD processes could only be probed in ultra-high vacuum by using electron and/or ion spectroscopy. Here we propose to investigate ICD processes by detection of the subsequently emitted characteristic fluorescence radiation, which makes their study in dense media possible. Three prototypical studies are planned. The first experiment will measure the time and energy resolved dispersed fluorescence on neon clusters to obtain characteristics of the emitted radiation in homogenous systems. In the second experiment, the advantage of fluorescence detection - the initial, intermediate, and final state selectivity - will be used to show directly the energy transport from one partner of a heterogeneous cluster to the other. The third experiment will apply the method to more complex targets, namely to H2O clusters. This project may finally expand experiments about the ubiquitous ICD process from artificial rare-gas clusters into omnipresent media, i.e. nano ice crystals (H2O clusters).