D.A. Knapp

TL;DR: In this article, an electron beam ion trap has been built for the production of very highly-charged ions and the study of their collisions with electrons, where a high density electron beam is used to trap, ionize and excite the ions for spectroscopic measurements.

TL;DR: The first measurements of electron-impact--excitation cross sections for very highly charged ions (Ba/sup 46 +/) are reported, and a powerful new technique for studying these ions is introduced.

TL;DR: The Electron Beam Ion Trap (EBIT) is a relatively new tool for the study of highly charged ions and its development has led to a variety of new experimental opportunities; measurements have been performed with EBITs using techniques impossible with conventional ion sources or storage rings.

TL;DR: In this paper, the authors reported the most sensitive direct upper limit set on the mass of the electron antineutrino of free molecular tritium yield, which corresponds to an upper limit of 9.3 eV (95% confidence level).

TL;DR: Polarization of two of the lines is strongly influenced by the hyperfine interaction with the Sc nucleus, demonstrating that polarization measurements can be used to investigate hyperfine interactions in highly ionized atoms.