Few-Body Dynamics in Simple Atomic Systems

简单原子系统中的少体动力学

• 批准号: 1703109
• 负责人: Michael Schulz
• 金额: $ 33万
• 依托单位: Missouri University of Science and Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1703109&HistoricalAwards=false
• 关键词: Few; Body; Dynamics; Simple; Atomic

Understanding how objects large and small move and interact with each other is essential in our knowledge of nature and in developing technologies. The interactions of even a small number of objects can be challenging to understand. The "few body problem" (FBP) of physics refers to scenarios where three or more objects mutually affect each other's trajectories. These scenarios arise in the gravitational interactions of planets and stars and in the electromagnetic interactions of atoms, ions, and electrons. At the microscopic scale, the laws of quantum mechanics also affect particle motions. The resulting dynamics are challenging to predict, but can be important for understanding atomic collisions and basic reactions. This project will study atom-electron-ion scattering to test new theories about the FBP in atomic systems. In particular, when the particles in the FBP obey the laws of quantum mechanics, then the wave-particle duality is important. This project will investigate how the nonlocal spatial extent, or coherence length, of the quantum mechanical waves that represent the particles can affect the way particles scatter from one another. This will lead to improved understanding of reaction cross sections and scattering theory. Many areas of science well beyond atomic physics are also concerned with the quantum mechanical FBP. Therefore, this research is relevant to a broad range of disciplines in science including nuclear physics, chemical physics, plasma science, and accelerator physics. Students working on this project will gain research experience with a broad range of experimental atomic physics technologies and theoretical analysis methods. Kinematically complete experiments will be performed that address two major themes. First, the reaction dynamics will be investigated for collisions under a broad range of conditions including some regimes with electron speeds close to the projectile speed. Second, projectile coherence effects, which concern a fundamental aspect of quantum mechanics, will be studied. Such experiments simultaneously determine the momentum vectors of all involved particles, i.e. the scattered projectiles, any ejected electron, and the recoiling residual target ions. From the data, reaction probabilities (cross sections) will be extracted as a function of numerous parameters. The data will provide sensitive tests of sophisticated theoretical models that depend on the transverse coherence length of the projectile beams. To better test these models the divergence of the beams, and hence the de Broglie wave coherence for the projectiles, will be manipulated in the experiment. In this way the impact of the projectile wave properties on the few-body dynamics in charged-particle interactions with atoms will be studied.

了解大大小小的物体如何移动和相互作用对于我们了解自然和开发技术至关重要。 即使是少量对象的相互作用也可能难以理解。 物理学中的“少体问题”（FBP）是指三个或更多物体相互影响彼此轨迹的情况。 这些场景出现在行星和恒星的引力相互作用以及原子、离子和电子的电磁相互作用中。 在微观尺度上，量子力学定律也影响粒子运动。由此产生的动力学很难预测，但对于理解原子碰撞和基本反应很重要。该项目将研究原子电子离子散射，以测试原子系统中 FBP 的新理论。特别是，当FBP中的粒子服从量子力学定律时，波粒二象性就很重要。该项目将研究代表粒子的量子机械波的非局域空间范围或相干长度如何影响粒子彼此散射的方式。这将提高对反应截面和散射理论的理解。原子物理学之外的许多科学领域也与量子力学 FBP 相关。因此，这项研究与广泛的科学学科相关，包括核物理、化学物理、等离子体科学和加速器物理。从事该项目的学生将获得广泛的实验原子物理技术和理论分析方法的研究经验。将进行运动学上完整的实验，以解决两个主要主题。首先，将研究各种条件下的碰撞反应动力学，包括电子速度接近弹丸速度的某些情况。其次，将研究涉及量子力学基本方面的射弹相干效应。此类实验同时确定所有涉及粒子的动量矢量，即散射的射弹、任何喷射的电子和反冲的残留目标离子。从数据中，将提取反应概率（横截面）作为众多参数的函数。这些数据将为复杂的理论模型提供敏感的测试，这些模型取决于射弹束的横向相干长度。为了更好地测试这些模型，将在实验中控制光束的发散度，从而控制射弹的德布罗意波相干性。通过这种方式，将研究抛射波特性对带电粒子与原子相互作用的少体动力学的影响。

项目成果

Fully Differential Study of the Few-Body Dynamics in Multi-Electron Atomic Fragmentation Processes

多电子原子碎裂过程中少体动力学的全微分研究

• 发表时间: 2017-01
• 期刊: molecular and optical physics
• 作者: Y. Gao; S. F.
• 通讯作者: S. F.

Fully Differential Study of Dissociative Single Capture and Coulomb Explosion through Double Capture in p + H2 Collisions

p H2 碰撞中解离单捕获和双捕获库仑爆炸的全微分研究

• 发表时间: 2017-01
• 期刊: Physical review. A
• 作者: B.R. Lamichhane; A. Hasan
• 通讯作者: A. Hasan

Target dependence of postcollision interaction effects on fully differential ionization cross sections

碰撞后相互作用效应对全微分电离截面的目标依赖性

• DOI: 10.1103/physreva.100.032707
• 发表时间: 2019-09
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: Dhital, M.;Bastola, S.;Silvus, A.;Lamichhane, B. R.;Ali, E.;Ciappina, M. F.;Lomsadze, R.;Hasan, A.;Madison, D. H.;Schulz, M.
• 通讯作者: Schulz, M.

Comparison of Experimental and Theoretical Fully Differential Cross Sections for Single Ionization of the 2s and 2p States of Li by Li2+ Ions

Li2 离子单电离 Li 2s 和 2p 态的实验和理论全微分截面比较

• 发表时间: 2017-01
• 期刊: molecular and optical physics
• 作者: E. Ghanbari

Signatures of autoionization in the angular electron distribution in two-photon double ionization of Ar

Ar双光子双电离中角电子分布的自电离特征

• DOI: 10.1103/physreva.98.033408
• 发表时间: 2018-09-17
• 期刊: Physical Review A
• 影响因子: 2.9
• 作者: S. Augustin;M. Schulz;G. Schmid;K. Schnorr;E. Gryzlova;H. Lindenblatt;S. Meister;Yifan Liu;F. Trost;L. Fechner;A. Grum;S. M. Burkov;M. Braune;R. Treusch;M. Gisselbrecht;C. Schröter;T. Pfeifer;R. Moshammer
• 通讯作者: R. Moshammer