Electron-collision induced fragmentation and intermolecular energy transfer processes in water and hydrated biomolecule clusters studied with multi-particle coincidence experiments

本项目旨在探索低能电子碰撞诱导的分子电离、碎裂和分子间能量转移等与DNA辐射损伤相关的反应。一个中心点是探索自然环境(如附着的水分子)对生物分子(BM)的分解可能产生的强烈影响。这里特别感兴趣的将是分子间库仑衰变(ICD)以及与BM有关的分子团簇中的相关能量和电荷转移过程，这些过程基本上是未知的。例如，从水到BM的能量转移一方面可以加强碎裂，另一方面在相反方向上的快速能量转移可以抑制碎裂。首先，将对四氢呋喃(THF)进行实验，四氢呋喃是DNA主干中脱氧核糖的最简单分子类似物。将使用带有低能电子束和可加热超音速分子喷射靶的多粒子成像光谱仪。这一全球独一无二的实验装置通过有效地测量所有电子和离子(它们的质量、电荷、方向和能量)，特别适合于研究电子驱动的分裂过程。三重至五重符合实验将以高碎片离子质量分辨率和高能量分辨率进行。

This project aims to explore low-energy electron impact-induced molecular ionization, fragmentation and intermolecular energy transfer which are reactions relevant in radiation damage of DNA. One central point is to explore the presumably strong influence of a natural environment like attached water molecules on the break-up of bio-molecules (BM). Here of particular interest will be the intermolecular Coulombic decay (ICD) and related energy and charge transfer processes in molecular clusters which in relation with BM are essentially unexplored. E.g., energy transfer from water to the BM on one hand can enhance fragmentation and on the other hand fast energy transfer in the reverse direction can quench fragmentation. First experiments will be performed on tetrahydrofuran (THF) the simplest molecular analog of deoxyribose in the DNA backbone. A multi-particle imaging spectrometer with an implemented low energy electron beam and a heatable supersonic molecular jet target will be used. This worldwide singular experimental set-up is uniquely suited to study electron-driven break-up processes by efficiently measuring all the electrons and ions (their mass, charge, direction and energy). Triple- up to quintuple- coincidence experiments will be performed with high fragment ion mass resolution and high energy resolution.