高电荷态重离子与原子近距离剧烈碰撞的快反冲离子动量谱学研究

Violent close collision between ions and atoms is a kind of typical violent interaction process of quantum systems involving multi-body, multi-degree of freedom. It provides an excellent test on dynamics of quantum multi-body systems. However, the present experimental techniques are hard to efficiently obtain more precise physical information, which are still limited to measure the energies and the angular distributions of the recoil or scatter ions, or their coincidence measurements..In this project, a novel fast recoil ion momentum spectroscopy, with a new layout is proposed, which is able to eliminate the huge amount of interference events produced in distant collisions and breaks the limitations of conventional recoil ion momentum spectroscopy with gas target. Combined with the 320 kV platform for multi-discipline research with highly charged ions at our institute, investigations on violent close collisions between highly charged ions and atoms will be promoted to a new stage of momentum measurement of recoil ions. Double differential cross sections will be obtained in collisions between highly charged Ar, Kr, Xe ions and carbon nanomembranes, and effective potentials corresponding to some typical reaction channels will be deduced.

离子-原子的近距离剧烈碰撞是一种典型的多体、多自由度参与的量子体系间的剧烈碰撞过程，是研究强扰动下量子多体系统动力学演化的一个理想实验对象。然而，当前其实验研究手段仍限于传统的散射、反冲离子能谱及角分布测量，或其符合测量，难以高效地获得更精细的物理信息。.本项目突破常规气体靶反冲离子动量谱学（RIMS）方法的限制，提出一种全新布局的快反冲离子动量谱学（FRIMS）方案，可剔除巨量远距离碰撞干扰事件。结合我所的320 kV高电荷态离子综合研究平台，可将高电荷态离子-原子近距离剧烈碰撞实验研究推进到反冲离子动量矢量测量新阶段。并以高电荷态Ar、Kr、Xe离子与碳纳米膜碰撞为例，实验获得双重微分截面，给出若干典型反应道所对应的不同等效势。

本项目针对高电荷态重离子与原子近距离剧烈碰撞过程，提出了一种全新的快反冲离子动量谱学（FRIMS）技术。该技术可将近距离剧烈碰撞研究推进到反冲动量测量阶段；并根据测量的反冲离子的落点位置和飞行时间，鉴别碰撞的各种可能反应道，获得相应的双重微分截面。本项目执行期间，主要的阶段性成果有：设计、加工、安装、调试了第一台快反冲离子动量谱仪装置，包括发展了快反冲离子引导电场构型，研制了大面积的二维位置灵敏MCP探测器和定时MCP探测器，制备了多种薄膜靶，搭建了散射离子-反冲离子符合测量数据获取系统；开展了多次测试实验，并对装置进行了多次改进和优化；发展了反演算法，编写了实验结果批处理程序，并对谱仪的反演精度进行了评估。.项目执行期间，已发表期刊论文11篇，申请发明专利7项，其中5项已授权；毕业1名博士生，2名硕士生。目前，初步实验已完成，实验数据的系统分析尚未完成。谱仪仍需进一步优化，下一阶段将开展系统的实验研究。