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Search Publications by: Joseph Reader (Assoc)

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Displaying 1 - 25 of 136

Mercury in the HgMn Stars X Lupi and HR 7775

October 12, 2021
Author(s)
C R. Proffitt, T Brage, D S. Leckrone, G Wahlgren, J C. Brandt, Craig J. Sansonetti, Joseph Reader, S Johansson
Observations of mercury lines in the HgMn stars chi Lupi and HR 7775 made with the Hubble Space Telescope's Goddard High Resolution Spectrograph are presented and analyzed. In chi Lupi we find that all observed lines are consistent with the same isotopic

Spectral Data for Gallium: Ga I through Ga XXXI

October 12, 2021
Author(s)
T Shirai, Joseph Reader, Alexander Kramida, J Sugar
The energy levels and spectral lines of gallium atom in all stages of ionization have been compiled. Experimental data on spectral lines and energy levels exist for spectra Ga I through Ga VII, Ga XXIII through Ga XXVI, and Ga XXX. For Li-like Ga XXIX

The Spectrum of Singly Ionized Potassium, K II

October 12, 2021
Author(s)
K Pettersen, J O. Ekberg, I Martinson, Joseph Reader
Using 10.7 m and 3-m normal-incidence vacuum ultraviolet spectrographs, we investigated the spectrum of singly ionized potassium in the regions 495 612 and 1247 2150 . More than 120 new K II lines were identified. The previous work on this spectrum was

The Cu II Spectrum

February 24, 2017
Author(s)
Alexander Kramida, Gillian Nave, Joseph Reader
New wavelength measurements in the vacuum ultraviolet (VUV), ultraviolet and visible spectral regions have been combined with available literature data to refine and extend the description of the spectrum of singly ionized copper (Cu II). In the VUV region

Optics

February 19, 2017
Author(s)
Joseph Reader
The field of optics is summarized to assist in the solution of practical optics problems by working scientists. Over seventy formulas are presented dealing with reflection and refraction, absorption, lenses, mirrors, diffraction, interference, and spectra

Spectrum and Energy Levels of Four-Times Ionized Yttrium (Y V

December 21, 2016
Author(s)
Joseph Reader
We present an extended analysis of the spectrum of four-times-ionized yttrium Y V. The analysis is based on spectrograms made with sliding-spark discharges on 10.7 normal- and grazing-incidence spectrographs. The measurements cover the region 184-2549 Å

Spectrum and Energy Levels of Five-Times Ionized Zirconium (Zr VI)

January 5, 2016
Author(s)
Joseph Reader, Mark D. Lindsay
The spectrum of five-times-ionized zirconium Zr VI was observed from 160 Å to 2000 Å with sliding spark discharges on 10.7-m normal- and grazing-incidence spectrographs. The existing analysis of this spectrum [Khan Z. A. et al. 1985 Phys. Scr. 31 837] was

Spectrum and Energy Levels of Quadruply-Ionized Molybdenum (Mo V)

May 28, 2015
Author(s)
Joseph Reader, Tauheed Ahmad
The spectrum of quadruply-ionized molybdenum Mo V was observed from 200 Å to 4700 Å with sliding spark discharges on 10.7-m normal- and grazing-incidence spectrographs. The existing analyses of this spectrum [Tauheed A et al. 1985 Phys. Scr. 31 369; Cabeza

NIST program of spectroscopic data for light elements of fusion interest

January 15, 2015
Author(s)
Joseph Reader, Alexander Kramida, Yuri Ralchenko, Wolfgang L. Wiese, Jeffrey R. Fuhr
This paper summarizes work at the National Institute of Standards and Technology (NIST) in support of the IAEA Coordinated Research Project on “Light Element Atom, Molecule and Radical Behaviour in the Divertor and Edge Plasma Regions.” It includes

EUV spectra of Rb-like to Ni-like dysprosium ions in an electron beam ion trap

August 12, 2014
Author(s)
Deirdre Kilbane, G. O'Sullivan, Yuri A. Podpaly, John D. Gillaspy, Joseph Reader, Yuri Ralchenko
Extreme ultraviolet radiation emitted from highly-charged dysprosium ions was measured at the National Institute of Standards and Technology. The ions were created, trapped, and excited in an electron beam ion trap (EBIT), and the spectra were recorded

Extreme ultraviolet spectra and analysis of ?n=0 transitions in highly charged barium

July 4, 2014
Author(s)
Joseph Reader, John D. Gillaspy, Dmitry D. Osin, Yuri Ralchenko
Extreme ultraviolet spectra of highly charged barium atoms were produced with an electron beam ion trap (EBIT) and recorded with a flat-field grazing-incidence spectrometer. The spectra were measured in the wavelength range 4 nm to 24 nm with the beam

EUV spectra from N-shell ions of Gd, Dy and W

September 23, 2013
Author(s)
Deirdre Kilbane, John D. Gillaspy, Yuri Ralchenko, Joseph Reader, G. O'Sullivan
Measurements of extreme ultraviolet radiation from gadolinium, dysprosium and tungsten ions with an open n=4 shell were performed at the National Institute of Standards and Technology. The ions were produced and confined in an electron beam ion trap and

Magnetic-dipole lines in 3dn ions of high-Z elements: identification, diagnostic potential, and dielectronic resonances

September 23, 2013
Author(s)
Yuri Ralchenko, John D. Gillaspy, Joseph Reader, Dmitry D. Osin, John J. Curry, Yuri A. Podpaly
We present a review of measurements and analyses of extreme-ultraviolet magneticdipole (M1) lines in 50-60-times ionized atoms of tungsten, hafnium, tantalum, and gold with an open 3d shell. The spectra were measured with the electron beam ion trap at the

Transition Energies of the D-lines in Na-like Ions

June 5, 2013
Author(s)
John D. Gillaspy, Dmitry D. Osin, Yuri Ralchenko, Joseph Reader, S A. Blundell
The NIST electron beam ion trap (EBIT) was used to measure the D1 (3s-3p1/2) and D2 (3s-3p3/2) transitions in Na-like ions of xenon, barium, samarium, gadolinium, dysprosium, erbium, tungsten, platinum, and bismuth. New relativistic many-body perturbation

1932 A watershed year in nuclear physics

March 4, 2013
Author(s)
Joseph Reader, Charles W. Clark
1932 was the year for an amazing series of discoveries in physics. This started with the announcement of the discovery of deuterium, followed by the discoveries of the neutron and the positron, as well as artificial disintegration of nuclei by accelerators

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

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

Light, atoms and nuclei: the optical discovery of deuterium

May 1, 2012
Author(s)
Charles W. Clark, Joseph Reader
Deuterium was discovered by atomic spectroscopy 80 years ago, and led to the rapid development of nuclear energy and isotope chemistry. Atomic spectroscopy of deuterium remains vibrant, with a recent application to understanding the early universe.

Extension and new level optimization of the Ne IV spectrum

January 13, 2012
Author(s)
Alexander Kramida, C M. Brown, Uri Feldman, Joseph Reader
Spectra of Ne emitted by a Penning discharge were recorded in the extreme ultraviolet (EUV) region between 140 Å and 359 Å on a 10.7 m grazing-incidence spectrograph with phosphor storage image plates. These spectra provided 33 newly identified lines of Ne