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Search Publications by: Joseph Reader (Assoc)

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Displaying 51 - 75 of 271

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

Atomic Spectroscopic Databases at NIST

October 28, 2010
Author(s)
Joseph Reader, Alexander Kramida, Yuri Ralchenko
We present recent work at NIST to develop and maintain databases for spectra, transition probabilities, and energy levels of atoms that are astrophysically important. We also describe our programs to critically compile these data as well as the recently

Extension of the resonance line series of Mg III

December 1, 2009
Author(s)
C M. Brown, Alexander Kramida, Uri Feldman, Joseph Reader
Spectra of Mg emitted by a Penning discharge were recorded in the extreme ultraviolet (EUV) on a 10.7-m grazing-incidence spectrograph with phosphor image plates. The spectra provided nine new lines of Mg III between 156 and 166 Å and allowed us to improve

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

Atomic Data for Lighting Applications

October 16, 2008
Author(s)
Gillian Nave, Craig J. Sansonetti, Joseph Reader
A major objective of our research program is the observation of spectra of rare earth elements in support of our program of atomic data measurements for lighting applications. Three years ago, NIST acquired a high-resolution Fourier transform spectrometer

Reference Wavelengths for Strong Lines of Atomic Hydrogen and Deuterium

October 16, 2008
Author(s)
Joseph Reader
Wavelengths of the individual fine-structure components of the n=1-2(Ly alpha), n=1-3(Ly beta), n=1-4(Ly gamma), n=1-5(Ly delta), n=1-6(Ly epsilon), n=1-7(Ly xi), n=2-3(H alpha), n=2-4(H beta), n=2-5(H gamma), and n=2-6(H delta), and n=2-7(H epsilon)

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

Extended EUV and UV Spectrum of Ne II

July 1, 2006
Author(s)
Alexander Kramida, C M. Brown, Uri Feldman, Joseph Reader
The extreme ultraviolet (EUV) spectrum of Ne emitted by a Penning discharge has been recorded at high resolution with a 10.7 m grazing incidence spectrometer. Based on the recorded spectra 75 new Ne II lines have been observed between 286 and 325

Performance of the GHRS Pt-Ne Hollow-Cathode Lamps After Their Return From Space and Comparison With Archival Data

May 1, 2006
Author(s)
F Kerber, D Lindler, P Bristow, Gillian Nave, Joseph Reader, Craig J. Sansonetti, D Lembke, S Heap, Michael R. Rosa, H J. Wood
The Space Telescope European Co-ordinating Facility (ST-ECF) and the National Institute of Standards and Technology (NIST) are collaborating to study hollow cathode calibration lamps as used onboard the Hubble Space Telescope (HST). As part of the STIS