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Search Publications by: John D. Gillaspy (Fed)

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Displaying 26 - 50 of 157

EUV Spectral Lines of Highly-Charged Hf, Ta and Au Ions Observed with an Electron Beam Ion Trap

January 12, 2011
Author(s)
Ilija Draganic, Yuri Ralchenko, Joseph Reader, John D. Gillaspy, Joseph N. Tan, Joshua M. Pomeroy, Samuel M. Brewer, Dmitry D. Osin
Extreme ultraviolet spectra of highly charged hafnium, tantalum, and gold were produced with an electron beam ion trap (EBIT) at the National Institute of Standards and Technology (NIST) and recorded with a flat-field grazing-incidence spectrometer in the

Progress at NIST in measuring the D-lines of Li isotopes using an optical frequency comb

December 20, 2010
Author(s)
Clayton Simien, Samuel M. Brewer, Joseph N. Tan, John D. Gillaspy, Craig J. Sansonetti
Precise spectroscopic experiments with light atoms can provide information about nuclear properties that are very difficult to obtain in electron scattering experiments. For example, relative nuclear radii of low-Z isotopes can be determined accurately

X-Ray Spectroscopy of Highly Charged Ions in Laboratory and Astrophysical Plasmas

September 1, 2010
Author(s)
E. H. Silver, N Brickhouse, T. Lin, G X. Chen, K. Kirby, John D. Gillaspy, Joseph N. Tan, J M. Laming
This paper presents (1) new laboratory data on the x-ray spectra of He-like Ar XVII over a broad spectral range (300-3500 eV) at high resolution (2) the results of new measurements of K-shell x- ray reference lines in carbon, oxygen, iron, copper, and

First Measurement of Lyman Alpha X-ray Lines in Hydrogen-like Vanadium

September 30, 2009
Author(s)
John D. Gillaspy, C T. Chantler, D Paterson, Lawrence T. Hudson, F Serpa, E Takacs
The first measurement of hydrogen-like vanadium x-ray Lyman alpha transitions has been made. The measurement was made on an absolute scale, fully independent of atomic structure calculations. Sufficient signal was obtained to reduce the statistical

Measurement of the D Line Doublet in High-Z Highly-Charged Sodium-like Ions

July 8, 2009
Author(s)
John D. Gillaspy, Ilija Draganic, Yuri Ralchenko, Joseph Reader, Joseph N. Tan, Joshua M. Pomeroy, Samuel M. Brewer
We report a direct observation of the D line doublet of sodium-like ions with Z≥72. Spectra in the 1 nm to 9 nm spectral range are presented showing the widely split doublet for Hf61+, Ta62+, W63+,and Au68+. The ions were produced and confined in an

Spectra of W 39+ -W 47+ in the 12 nm to 20 nm Region Observed With an EBIT Light Source

October 14, 2007
Author(s)
Yuri Ralchenko, Joseph Reader, Joshua M. Pomeroy, Joseph N. Tan, John D. Gillaspy
We observed spectra of highly ionized tungsten in the extreme ultraviolet with an electron beam ion trap (EBIT) and a grazing incidence spectrometer at the National Institute of Standards and Technology. Stages of ionization were distinguished by varying

The Potential of Highly Charged Ions: Possible Future Applications

September 1, 2007
Author(s)
John D. Gillaspy, Joshua M. Pomeroy, A C. Perrella, Holger Grube
This paper mirrors and provides references to an invited review talk delivered by the first author at the 13th International Conference on the Physics of Highly Charged Ions. It briefly updates and extends an earlier review given in 2001 [1].

Selectable Resistance-Area Product by Dilute Highly Charged Ion Irradiation

August 13, 2007
Author(s)
Joshua M. Pomeroy, Holger Grube, A C. Perrella, John D. Gillaspy
In order to provide high performance read heads for future hard drive densities, considerable effort worldwide has been invested in developing techniques for producing low resistance area product (RA) magnetic tunnel junction sensors. In this letter, we

Gold Nanostructures Created by Highly Charged Ions

June 28, 2007
Author(s)
Joshua M. Pomeroy, Holger Grube, A C. Perrella, John D. Gillaspy
Nanometer sized structures produced by individual highly charged ion (HCI)impacts are reported for the first time on a high conductivity surface andexamined by scanning tunnelling microscopy (STM). Highly charged ions, e.g.,Bi$^{81+}$, represent an exotic

EUV Spectroscopy of Highly Charged Xenon Ions Created Using an Electron Beam Ion Trap

March 27, 2007
Author(s)
K Fahy, E Sokell, G O'Sullivan, A Aguilar, Joshua M. Pomeroy, Joseph N. Tan, John D. Gillaspy
At the NIST Electron Beam Ion Trap (EBIT), extreme-ultraviolet spectra of xenon ions have been recorded using a flat-field spectrometer. The electron beam energy was varied from 180 eV to 8 keV and radiation from charge states Xe6+ to Xe43+ was observed