First Observation of Multiply Charged Vanadium Clusters in a Penning Trap

1997

EBIT trapping program

1993

The LLNL electron beam ion trap provides the world's only source of stationary highly charged ions up to bare U. This unique capability makes many new atomic and nuclear physics experiments possible.

Pulsed gas injection for X-ray spectroscopy of highly charged ions stored in the magnetic trapping mode of an electron beam ion trap

1998

Abstract Highly charged atoms produced in an electron beam ion trap were stored after the electron beam was turned off by operating the trap in the magnetic trapping mode. Such storage allowed monitoring charge exchange reactions between the stored ions and residual neutral gas present in the trap by X-ray detection. The charge exchange reactions were enhanced by the application of a pulse of neutral gas. The method was exemplified for the case of H-like uranium interacting with neutral neon, where the K-shell X-rays and the series limit for the electron capture of U91+ were observed.

First Fourier-transform ion cyclotron resonance signals of very highly charged atomic ions

1994

We report on the first application of Fourier-transform ion cyclotron resonance mass spectrometry to the very highly charged ions produced in the high-energy electron beam ion trap (SuperEBIT) at the Lawrence Livermore National Laboratory. Initial results are described, and spectra are presented from ions as highly charged as Cs53+.

Fourier transform-ion cyclotron resonance mass spectrometry — A new tool for measuring highly charged ions in an electron beam ion trap

1995

Abstract Fourier transform-ion cyclotron mass spectrometry has been applied to the study of highly charged ions produced and confined in an electron beam ion trap. Measurements of the relative ion abundance of hydrogenlike and bare krypton ions were made and compared to the abundance ratios determined with standard X-ray techniques. Good agreement was found establishing the reliability of the method as a new tool in highly charged ion research.

FTICR analysis of the magnetic trapping mode of the electron beam ion trap

1996

Abstract An electron beam ion trap is used to produce and confine highly-charged atomic ions in an energetic electron beam (electron trapping mode). After switching off the electron beam the ions remain trapped due to the external magnetic and electric fields. We have investigated the properties of this magnetic trapping mode by use of Fourier transform ion cyclotron resonance mass spectrometry. We found that the number of highly charged ions and the relative species abundance is nearly the same just before and just after turning off the electron beam. The electron trapping mode thus represents an ideal method for filling the trap in situ without the losses associated with transferring the …

Measurement and interpretation of the polarization of the x-ray line emission of heliumlike Fe XXV excited by an electron beam

1996

The linear polarization of the 1s2p${\mathrm{}}^{1}$${\mathit{P}}_{1}$\ensuremath{\rightarrow}1${\mathit{s}}^{2}$${\mathrm{}}^{1}$${\mathit{S}}_{0}$ resonance line, the 1s2p${\mathrm{}}^{3}$${\mathit{P}}_{1,2}$\ensuremath{\rightarrow}1${\mathit{s}}^{2}$${\mathrm{}}^{1}$${\mathit{S}}_{0}$ intercombination lines, and the 1s2s${\mathrm{}}^{3}$${\mathit{S}}_{1}$\ensuremath{\rightarrow}1${\mathit{s}}^{2}$${\mathrm{}}^{1}$${\mathit{S}}_{0}$ forbidden line was measured in heliumlike Fe XXV excited near threshold by a monoenergetic electron beam. The measurement was carried out with a high-resolution x-ray spectrometer employing a set of two analyzing crystals that acted as polarizers by selectivel…

Production and investigation of multiply charged metal clusters in a Penning trap

1996

Singly charged gold cluster ions from a laser-vaporization source are transferred into a Penning trap and subjected to electron bombardment. The charged reaction products are analyzed by time-of-flight mass spectrometry after axial ejection from the trap. They include singly charged cluster fragments, multiply charged clusters of the initial size and multiply charged cluster fragments. The multiply charged clusters are selected and further investigated by collision induced dissociation. Two types of reactions can be distinguished: Dissociation into several charged fragments and evaporation of neutrals. Several features of multiply charged clusters relevant for future investigations are revi…

X-ray measurements of charge transfer reactions involving cold, very highly charged ions

1999

The magnetic trapping mode of the Livermore high-energy Electron Beam Ion Trap is exploited to study charge transfer reactions between cold (few eV/amu) highly charged ions and gases. By selectively puffing neutral gases and monitoring the x-ray emission, state-selective measurements of the charge transfer reaction channels are possible. The observed K-shell x-ray spectra show prominent emission from high-n levels decaying to the n = 1 ground level, which is enabled by electron capture into states with low orbital angular momentum. A comparison with modeling calculations, therefore, allows a determination of the range of principal and angular momentum quantum numbers involved in the reactio…