Production and Exploration of Rydberg Highly Charged Ions

Clemson University, Clemson SC

Investigators

Abstract

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.