Production and Exploration of Rydberg Highly Charged Ions

该项目将促进对Rydberg高电荷离子（RyHCI）形成和衰变的认识。高电荷离子是指全部或大部分电子被剥离，剩下的电子存在于原子核的巨大电场中的原子。这些系统中电子跃迁的测量为极端条件下的物理预测提供了严格的测试。Rydberg高电荷离子，其中剩余的电子处于高度激发态，将是这个项目的重点。这些系统为基本常数的测量、量子信息处理方案、量子电动力学的精密测试和精密x射线波长标准提供了测试平台。这种极端电子态的形成并不简单，因为激发能比普通激光可达到的跃迁高许多个数量级。研究活动还包括在原子物理学、光谱学、数据分析、科学研究和科学传播方面培训下一代科学家。除研究生外，该团队还将通过克莱姆森大学的校园研究计划指导本科生，如针对在校学生的创意探究计划和尤里卡！为即将入学的本科生提供的项目。本研究的总体目标是创造和研究Rydberg高电荷离子（RyHCI），其中单个电子占据高主量子数态。从中性原子碰撞到裸核的里德堡能级的单电子捕获将被用作这些独特的类h系统的产生机制。导致这些单电子离子形成的电荷交换过程还远远没有被完全理解，因此这些结果也将有助于理解原子物理学中的这一重要问题。该团队将在克莱姆森大学电子束离子阱（CUEBIT）设施中创建不同动能的HCI光束，并将它们与气体喷射目标的不同中性原子相交。高分辨率和宽带x射线光谱仪将被用于观察与交替级联通道同时直接向基态的转变。RyHCI中的谱线将作为电子捕获的初始（n,l）分布的特征。此外，该团队将与理论家合作，使用碰撞级联模型来确定初始捕获的位置分布，并将他们的发现与理论计算（包括经典轨迹蒙特卡罗模拟）进行比较。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will advance knowledge about the formation and decay of Rydberg highly charged ions (RyHCI). Highly charged ions are atoms in which all or most of their electrons have been stripped and the remaining electron(s) exist in the extremely large electric field of the nucleus. Measurements of electronic transitions in these systems provide stringent tests of physics predictions in extreme conditions. Rydberg highly charged ions, in which the remaining electron is in a highly excited state, will be the focus of this project. These systems provide test beds for measurement of fundamental constants, quantum information processing schemes, precision tests of quantum electrodynamics, and precision X-ray wavelength standards. The formation of such extreme electronic states is not straightforward, due to excitation energies that are many orders of magnitude higher than that of ordinary laser accessible transitions. The research activity also involves training of next generation scientists in atomic physics, spectroscopy, data analysis, scientific research, and scientific communication. In addition to graduate students, this team will mentor undergraduate students through Clemson University's on-campus research initiatives such as the Creative Inquiry program for current students and the Eureka! program for incoming undergraduates.The overall goal of this research is to create and investigate Rydberg highly charged ions (RyHCI) in which a single electron occupies high principle quantum number states. Single electron capture from colliding neutral atoms into the Rydberg levels of bare nuclei will be employed as a production mechanism for these unique H-like systems. The charge exchange process that leads to the formation of these one-electron ions is far from being fully understood, and therefore the results will also contribute to the understanding of this important problem in atomic physics. This team will create HCI beams of different kinetic energies at the Clemson University Electron Beam Ion Trap (CUEBIT) facility and intersect them with different neutral atoms of a gas jet target. High-resolution and broadband X-ray spectrometers will be used to observe transitions directly to the ground state simultaneously with alternative cascade channels. Spectral lines in RyHCI will serve as signatures for the initial (n,l) distribution of the electron capture. Additionally, this team will collaborate with theoreticians to use a collisional cascade model to determine the site distribution of the initial capture and compare their findings with theoretical calculations including classical trajectory Monte Carlo simulations.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.