RUI: Photoionization, Time Delay, Positronium Formation, and Ion Impact Studies of Fullerenes, Endofullerenes, and Atoms

RUI：富勒烯、内富勒烯和原子的光电离、时间延迟、正电子形成和离子撞击研究

基本信息

批准号：
1806206
负责人：
HIMADRI CHAKRABORTY
金额：
$ 30万
依托单位：
Northwest Missouri State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-15 至 2022-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1806206&HistoricalAwards=false
关键词：
RUI Photoionization Time Delay Positronium

项目摘要

By shining the laser light on an atom or by colliding the atom with charged particles one can probe the atom's response to such external stimuli. These are powerful scientific methods to learn fundamental properties of materials. Using these techniques to systems more complex than atoms and of direct applied interest is therefore beneficial for the advancement of basic science and technology. The systems to be studied in the current research are Buckminster fullerenes and other larger fullerenes, including atoms/clusters caged inside these molecules, called endofullerenes. These materials hold the promise of exciting applications in areas including quantum computations, superconductivity, biomedical fields, drug delivery research, magnetic resonance imaging, and organic photovoltaics. Hence, understanding the physical and chemical structure and response properties of these systems, including the influence of the fullerene cage on the behavior of the confined species, are matters of great scientific interest. Using large scale computer simulations the program aims to investigate how electrons inside the systems collectively interacts with each other to move internally or to exit the system and how much time they spend to reach the detector. How do the structure and geometry of the system play roles in the mechanism? This will be investigated both for light and fast-ion impact. By choosing exotic antiparticles like positrons to impact on fullerenes the study of the formation of electron-positron pairs, the positronium, is a novel direction of the program.Numerical methods to be employed to model the systems and their response are based on Density Functional Theory. These methods will also be used to calculate the intensity of the emerging electron flux from the system along a specific direction and/or in all directions. From the complex variation of the detected electron flux as a function of the laser energy or the ion-impact energy researchers will extract valuable information about the system. Furthermore, the time of flight of the electrons from the irradiated target to the detector will be computed and the variation in this flight-time as a function of laser frequency will enable further insights into the scientific processes. Following the impact of positrons, the formation of the positronium (Ps) is a vital process in nature, although no attempt of Ps formation using gas-phase fullerene systems has been made until recent research that came from this program. The science to be learned from the study of Ps formation should be universal for Ps formation from nanosystems ushering new directions of Ps spectroscopy. In general, results are expected to motivate experiments and induce collaborations with experimental groups. Students and postdoctoral researchers will be involved for excellent experience in education and opportunities to become expert researchers.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

通过在原子上发光激光光或通过带电颗粒碰撞原子，可以探测原子对这种外部刺激的反应。这些是学习材料基本特性的强大科学方法。因此，将这些技术用于比原子更复杂的系统和直接应用的感兴趣对基础科学和技术的发展是有益的。当前研究中要研究的系统是Buckminster Fullerenes和其他较大的富勒烯，包括这些分子内部的原子/簇，称为Endofullerenes。这些材料有望在包括量子计算，超导性，生物医学领域，药物递送研究，磁共振成像和有机光伏的区域中进行令人兴奋的应用。因此，了解这些系统的物理和化学结构和响应特性，包括富勒烯笼子对被限制物种行为的影响，是极大的科学利益的问题。使用大型计算机模拟该程序旨在调查系统内部的电子如何共同相互交互以内部移动或退出系统以及他们花费多少时间到达检测器。系统的结构和几何形状如何在机制中起作用？这将在光线和快速离子撞击中进行调查。通过选择诸如正电子的异国情调反粒子对富勒烯的影响，对电子 - 尖素对的形成的研究（正电子）是该程序的新方向。。这些方法还将用于沿特定方向和/或在各个方向上计算系统中新兴电子通量的强度。从检测到的电子通量随激光能量的函数或离子影响能量研究人员的函数中，将提取有关系统的有价值信息。此外，将计算电子从辐照目标到检测器的飞行时间，并且该飞行时间随激光频率的函数的变化将有助于进一步了解科学过程。在正电子的影响之后，正电子（PS）的形成本质上是一个至关重要的过程，尽管直到该程序的最新研究都没有尝试使用PS形成。从PS形成的研究中要学到的科学对于从纳米系统形成的PS形成应该是普遍的，从而引导PS光谱的新方向。通常，结果有望激励实验并引起与实验组的合作。学生和博士后研究人员将参与获得教育和成为专家研究人员机会的良好经验。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响评估标准通过评估来支持的。

项目成果

期刊论文数量（18）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

A dynamical (e,2e) investigation into the ionization of pyrazine

DOI：
10.1016/j.cplett.2021.139000
发表时间：
2021-10
期刊：
Chemical Physics Letters
影响因子：
2.8
作者：
Darryl B Jones;E. Ali;H. Chakraborty;C. Ning;G. García;D. Madison;M. Brunger
通讯作者：
Darryl B Jones;E. Ali;H. Chakraborty;C. Ning;G. García;D. Madison;M. Brunger

A density functional theory based comparative study of hybrid photoemissions from Cl@C60, Br@C60 and I@C60

DOI：
10.1140/epjd/e2020-10140-6
发表时间：
2020-03
期刊：
The European Physical Journal D
影响因子：
0
作者：
D. Shields;R. De;E. Ali;M. Madjet;S. Manson;H. Chakraborty
通讯作者：
D. Shields;R. De;E. Ali;M. Madjet;S. Manson;H. Chakraborty

Resonant Charge-Transfer in Grazing Collisions of H− with Vicinal Nanosurfaces on Cu(111), Au(100) and Pd(111) Substrates: A Comparative Study

H 与 Cu(111)、Au(100) 和 Pd(111) 基底上邻位纳米表面掠碰撞中的共振电荷转移：比较研究

DOI：
10.3390/atoms7030089
发表时间：
2019
期刊：
Atoms
影响因子：
1.8
作者：
Shaw, John;Monismith, David;Zhang, Yixiao;Doerr, Danielle;Chakraborty, Himadri S.
通讯作者：
Chakraborty, Himadri S.

Molecular-size effects on diffraction resonances in positronium formation from fullerenes

分子尺寸对富勒烯形成正电子素衍射共振的影响