Threshold phenomena in electron impact ionisation of atoms explored by multi-particle imaging techniques

通过多粒子成像技术探索原子电子碰撞电离的阈值现象

• 批准号: 104713687
• 负责人: Dr. Xueguang Ren, Ph.D.
• 金额: --
• 依托单位: Physikalisch-Technische Bundesanstalt (PTB)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/104713687?language=en
• 关键词: Threshold; phenomena; electron; impact; ionisation

The here-proposed experiments investigate the interaction of electrons with atoms, being of decisive importance in all (technical) plasmas, in radiation tumour therapy as well as for materials research. The aim is to provide unique benchmark data (i) concerning fundamental questions of current interest and (ii) for technologically relevant targets by fully exploiting multi-particle imaging spectrometers (reaction microscopes) in combination with a high quality photo-cathode electron beam source: The unprecedented momentum resolution and efficiency of the set-up will allow to explore threshold double ionization for the target species helium and lithium. For the first time fully differential cross sections (FDCS) for these reactions will be able to verify threshold theories for four-body Coulomb fragmentation. This is a particularly hot topic since, in contradiction with well established models, recent theoretical works predict that the emission geometry of multi-electron threshold ionization critically depends on the initial configuration of the bound electrons and should be very different for helium and lithium.In parallel FDCS shall be measured for single ionisation of heavy, technologically relevant atoms and molecules, covering a large part of the final state momentum space, thus, ultimately testing theoretical predictions.

这里提供的实验研究了电子与原子的相互作用，在所有（技术）等离子体中，在辐射肿瘤疗法以及材料研究中具有决定性的重要性。目的是通过充分利用多粒子成像光谱仪（反应显微镜）以及高质量的照相电极电子光束来源来提供有关当前感兴趣的基本问题和（ii）的独特基准数据（i），以及（ii）技术相关的目标问题：启发了螺旋型和螺旋的效率。这些反应的完全差异横截面（FDC）首次能够验证四体库仑碎片的阈值理论。这是一个特别热门的话题，因为在与良好的模型矛盾的情况下，最近的理论工作预测，多电子阈值电离的发射几何形状在迫切地取决于绑定电子的初始配置，并且应在氦气和液化性方面非常不同。因此，最终测试理论预测。

项目成果

Low-energy electron-impact ionization of argon: Three-dimensional cross section

• DOI: 10.1103/physreva.85.032702
• 发表时间: 2012-03
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: X. Ren;T. Pflüger;J. Ullrich;O. Zatsarinny;K. Bartschat;D. Madison;A. Dorn

Strong molecular alignment dependence of H2 electron impact ionization dynamics.

• DOI: 10.1103/physrevlett.109.123202
• 发表时间: 2012-09
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: X. Ren;T. Pflüger;Shenyue Xu;J. Colgan;M. Pindzola;A. Senftleben;J. Ullrich;A. Dorn