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Search Publications by: John D. Gillaspy (Fed)

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Displaying 26 - 50 of 314

Light polarization and quantum interference effects in unresolvable atomic lines: application to a precise measurement of the 6,7Li D2 lines.

March 7, 2013
Author(s)
Roger C. Brown, Saijun Wu, James V. Porto, Craig J. Sansonetti, Clayton Simien, Samuel M. Brewer, Joseph N. Tan, John D. Gillaspy
We characterize the effect of quantum interference of light scattering on the line shapes and measured line positions in atomic spectra. These effects occur when the excited state splittings are of order the excited state line widths, and represent an

EUV magnetic-dipole lines from highly-charged high-Z ions with an open $3d$ shell

November 27, 2012
Author(s)
Yuri Ralchenko, John D. Gillaspy, Joseph Reader, Dmitry D. Osin
The electron beam ion trap (EBIT) at the National Institute of Standards and Technology was used to produce highly-charged ions of hafnium, tantalum and gold with an open $3d$ shell. The extreme-ultraviolet (EUV) spectra from these ions were recorded with

Testing Three-body Quantum Electrodynamics with Trapped Ti-20 Ions: Evidence for a Z-Dependent Divergence between Experiment and Calculation

October 10, 2012
Author(s)
Lawrence T. Hudson, C T. Chantler, Mark N. Kinnane, John D. Gillaspy, A.T. Payne, L F. Smale, Albert Henins, Joseph N. Tan, J A. Kimpton, E Takacs, K Makonyi, Joshua M. Pomeroy
We report the measurement of the w (1s2p 1P1 ! 1s2 1S0) resonance line transition energy in helium-like titanium. Our result, 4749.85(7) eV, deviates from the most recent ab initio prediction by three times our experimental uncertainty and by many times

EUV spectra of Rb-like to Cu-like gadolinium ions in an electron beam ion trap

October 8, 2012
Author(s)
Yuri Ralchenko, Deirdre Kilbane, G. O'Sullivan, John D. Gillaspy, Joseph Reader
Measurements of extreme ultraviolet radiation from highly-charged gadolinium ions were made at the National Institute of Standards and Technology. The ions were produced and confined in an electron beam ion trap (EBIT) and the spectra were recorded with a

Overview of Recent Atomic Spectroscopy At The NIST EBIT

May 5, 2012
Author(s)
John D. Gillaspy
Seven papers published by the NIST EBIT spectroscopy team and collaborators from mid-2009 to mid-2011 are summarized. Previous discussions of the D-lines in Na-like ions and the Lyman-alpha lines in H-like ions are updated with new information. Nine issues

Resource Letter SS-1: The Spin-Statistics Connection

April 4, 2012
Author(s)
Catalina Curceanu, John D. Gillaspy, R. C. Hilborn
This Resource Letter provides a guide to the literature on the Spin-Statistics Connection and related issues such as the Pauli Exclusion Principle and particle indistinguishability. Journal articles and books are cited for the following topics: basic

Absolute transition frequencies and quantum interference in a frequency comb based measurement of the 6,7Li D lines

July 6, 2011
Author(s)
Craig J. Sansonetti, Clayton Simien, John D. Gillaspy, Joseph N. Tan, Samuel M. Brewer, Roger C. Brown, Saijun Wu, James V. Porto
Optical frequencies of the D lines of 6,7Li were measured with a relative accuracy of 5x10-11 using an optical comb synthesizer. Quantum interference in the laser induced fluorescence for the partially-resolved D2 lines was found to produce polarization

Fe xvii X-ray Line Ratios for Accurate Astrophysical Plasma Diagnostics

February 20, 2011
Author(s)
John D. Gillaspy, E. H. Silver, L. Tedesco, Joseph N. Tan, Joshua M. Pomeroy, J M. Laming, G.-X. Chen, T. Lin
New laboratory measurements of the Ne-like Fe xvii x-ray lines in the 15-17 Angstrom range are presented, along with new theoretical predictions. These results establish consistency between independent laboratories and opens the door to trustworthy