电子碰撞生物分子电离解离的三维动力学实验研究

电子与原子分子（e，2e）碰撞电离过程是研究量子动力学的重要手段之一，在物理、化学、分子生物学和医学等领域中有着广泛的基础研究和应用价值。在研究生物大分子方面，已有的实验结果由于采用传统的转角度探测的方法，实验数据存在统计误差较大、探测角度范围有限和共面几何条件的局限性。本项目申请拟基于反应谱仪技术实现生物分子电子碰撞电离的三维动力学完全实验研究，利用反应谱仪高探测效率、高分辨率以及覆盖4pi立体角的多粒子符合实验测量的优势，从根本上解决现有生物分子实验研究中存在的上述问题。实验测量不同动力学条件下（入射电子能量、出射电子能量、散射角）交叉归一的三维空间全微分散射截面，全面、系统地研究生物分子（e，2e）反应的动力学过程。这将为发展适用于大分子计算的理论方法和模型提供高精度实验基准数据，为理解电子在多中心势中的运动规律和生物体系的辐射损伤机理提供重要的实验依据。

Electron-impact ionization of atoms and molecules is a fundamental process which is relevant to understand and interpret a wide range of scientific phenomenon and technological applications, including quantum few-body dynamics, plasma physics, planetary atmospheres, nuclear fusion and radiation-interactions with living tissue. The existing data of (e, 2e) on biomolecules are measured using the conventional (e, 2e) spectrometer which are limited by the experimental statistics, the electron angular range and the coplanar geometry. In the present project we aim to explore the dynamics of electron-impact ionization and fragmentation of tetrahydrofuran and uracil bio-relevant molecules by kinematically complete measurements. The experiments are performed using reaction microscope or COLTRIMS techniques in which the momentum vectors and consequently, the kinetic energies of final state electrons and ions are coincidentally measured by covering almost 4pi solid angles. Therefore, Benchmark data with highly improved statistics, cross-normalized and three-dimensional (3D) triple-differential cross sections will be obtained in the present project. This will provide a comprehensive study on the dynamics of (e, 2e) on biomolecules and understanding the role of the multi-center potential and the mechanisms of radiation damage of biological systems.