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Search Publications by: John D. Gillaspy (Fed)

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Displaying 76 - 100 of 157

Trapped Highly Charged Ion Plasmas

January 1, 2002
Author(s)
E Takacs, John D. Gillaspy
Electron beam Ion Trap (EBIT) devices are reviewed with special attention to applications in highly charged ion plasma research. EBIT properties are presented based on information extracted from a variety of experiments presented in the literature. Topics

Quantum Electrodynamics in the Dark

August 1, 2001
Author(s)
John D. Gillaspy
Perhaps they're just shy, but heavy atoms seem very uncomfortalbe when most of their electrons are stripped off. In order to cover their nakedness as quickly as possible, they aggressively try to steal electrons from any source they encounter. Their

Analysis of Broadband X-Ray Spectra of Highly Charged Krypton From a Microcalorimeter Detector of an Electron-Beam Ion Trap

April 1, 2001
Author(s)
I Kink, J M. Laming, E Takacs, James V. Porto, John D. Gillaspy, E Silver, H. Schnopper, Simon R. Bandler, M Barbera, N Brickhouse, S Murray, N. Madden, D Landis, J. Beeman, E. E. Haller
Spectra of highly charged Kr ions, produced in an EBIT, have been recorded in a broad x-ray energy band (0.3-4 keV) with a microcalorimeter detector. Most of the spectral lines have been identified as transitions of B- to Al-like Kr. The transition

Highly Charged Ions

January 1, 2001
Author(s)
John D. Gillaspy
This article reviews some of the fundamental properties of highly charged ions, the methods of producing them (with particular emphasis on table-top devices), and their use as a tool for both basic science and applied technology. Topics discussed include

In Situ Imaging of Highly Charged Ion Irradiated Mica

January 1, 2001
Author(s)
L P. Ratliff, John D. Gillaspy
We have studied the modification of mica surfaces due to the impact of Xe44+ ions by imaging the ion-exposed surfaces with atomic force microscopy in vacuum. By incorporating the microscope into the vacuum chamber where the samples are exposed to the ions

Microcalorimeter/EBIT Measurements of X-Ray Spectra of Highly Charged Ions

January 1, 2001
Author(s)
I Kink, J M. Laming, E Takacs, James V. Porto, John D. Gillaspy, E Silver, H. Schnopper, Simon R. Bandler, M Barbera, N Brickhouse, S Murray, D Landis, J. Beeman, E. E. Haller
Spectra of highly charged Ar, Kr, Xe and Fe ions, produced in an Electron Beam Ion Trap (EBIT), have been recorded in a broad x-ray energy band (0.2 keV to 10 keV) with a microcalorimeter detector. The first analysis of the Kr spectra has been completed

Separation of Inner Shell Vacancy Transfer Mechanisms in Collisions of Slow Ar 17+ Ions with SiO 2

January 1, 2001
Author(s)
E Takacs, Z Ber nyi, John D. Gillaspy, L P. Ratliff, Ronaldo Minniti, J Pedulla, R Deslattes, N Stolterfoht
We have studied the spectrum of x-rays emitted when hydrogen-like argon ions impact silicon dioxide surfaces. Specifically, we were interested in the mechanism for creation of K-shell holes in the silicon target atoms, which can be filled with the release

Emission-Line Intensity Ratios in FeXVII Observed with a Microcalorimeter on an Electron Beam Ion Trap

December 1, 2000
Author(s)
J M. Laming, I Kink, E Takacs, James V. Porto, John D. Gillaspy, E Silver, H. Schnopper, Simon R. Bandler, N Brickhouse, S Murray, M Barbera, A K. Bhatia, G. A. Doschek, N. Madden, D Landis, J. Beeman, E. E. Haller
We report new observations of emission line intensity ratios of Fe XVII under controlled experimental conditions, using the National Institute of Standards and Technology electron beam ion trap (EBIT) with a microcalorimeter detector. . . .Both R-matrix

Laboratory Astrophysics Survey of Key X-Ray Diagnostic Lines Using a Microcalorimeter on an Electron Beam Ion Trap

September 1, 2000
Author(s)
E Silver, H. Schnopper, Simon R. Bandler, N Brickhouse, S Murray, M Barbera, E Takacs, John D. Gillaspy, James V. Porto, I Kink, J M. Laming, N. Madden, D Landis, J. Beeman, E. E. Haller
Cosmic plasma conditions created in an Electron Beam Ion Trap (EBIT) make it possible to simulate the dependencies of Key diagnostic x-ray lines on density, temperature, and excitation conditions that exist in astrophysical sources. We used a

Direct Imaging of Highly Charged Ions in an Electron Beam Ion Trap

August 1, 2000
Author(s)
James V. Porto, I Kink, John D. Gillaspy
We have directly observed the ion cloud distribution in an electron beam ion trap using visible and ultraviolet fluorescence from lines in the ground term of Ar 13+,^ Xe 31+ and Xe 32+ ions. Using a gated intensified charge coupled device camera, we have

UV Light From the Ground Term of Ti-Like Ytterbium, Tungsten, and Bismuth

May 1, 2000
Author(s)
James V. Porto, John D. Gillaspy
We have used an electron beam ion trap (EBIT) to measure the wavelength of the J=2 to j=3 magnetic dipole transition in the 3d 4 ground term of Ti-like Ytterbium and Tungsten. These results extend the range of measurements of this line along the