Radiative Transition Probabilities and Stimulated Cross-Sections of Nd3+ in 3Ga2S3·La2S3(GLS) and 3Aℓ2S3·La2S3(ALS) GLASSES

1980 ◽  
pp. 463-468 ◽  
Author(s):  
R. Reisfeld ◽  
A. Bornstein ◽  
J. Flahaut ◽  
A. M. Loireau-Lazac’h
Keyword(s):  
Cross Sections ◽  
Transition Probabilities ◽  
Radiative Transition

scholarly journals Benchmarking Current Capabilities for the Generation of Excitation and Photoionisation Atomic Data

Galaxies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 90 ◽  
Author(s):  
Catherine Ramsbottom ◽  
Connor Ballance ◽  
Ryan Smyth ◽  
Andrew Conroy ◽  
Luis Fernández-Menchero ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Cross Sections ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Radiative Transition ◽  
Atomic Data ◽  
High Quality ◽  
Astronomical Instruments ◽  
First Time ◽  
Line Strengths

The spectra currently emerging from modern ground- and space-based astronomical instruments are of exceptionally high quality and resolution. To meaningfully analyse these spectra, researchers utilise complex modelling codes to replicate the observations. The main inputs to these codes are atomic data such as excitation and photoionisation cross sections, as well as radiative transition probabilities, energy levels, and line strengths. In this publication, the current capabilities of the numerical methods and computer packages used in the generation of these data are discussed. Particular emphasis is given to Fe-peak species and the heavy systems of tungsten and molybdenum. Some of the results presented to highlight certain issues and/or advances have already been published in the literature, while other sections present new recently evaluated atomic data for the first time.

scholarly journals Measurement of the A-Value of the Intersystem Transition in Al II at 2670 Å: Å Progress Report

1984 ◽  
Vol 86 ◽  
pp. 163-166
Author(s):  
B. Carol Johnson ◽  
H.S. Kwong
Keyword(s):  
Cross Sections ◽  
Radiative Decay ◽  
Transition Probabilities ◽  
Radiative Transition ◽  
Electron Excitation ◽  
Spectral Lines ◽  
Metastable Level ◽  
Astrophysical Plasmas ◽  
Atomic Ions ◽  
A Value

Ratios of intensities of spectral lines produced in the radiative decay of collisionally-excited levels of atomic ions are versatile indicators of electron density in astrophysical plasmas when one of the lines involves a metastable level (see the review by Feldman 1981 and references therein). Radiative transition probabilities (A-values) and electron excitation cross sections are necessary for accurate, quantitative analyses of these plasmas. The work reported here is part of a program of measurements of astrophysically interesting A-values and radiative lifetimes (see the review by Smith et al. 1984); until we began, such anaylyses of astrophysical plasmas depended upon unconfirmed calculated A-values.

Fluorescence and Judd-Ofelt Analysis of Er3+ Doped CaF2 Transparent Ceramic

2014 ◽  
Vol 875-877 ◽  
pp. 23-27
Author(s):  
Ru Zhen Xing ◽  
Bing Chu Mei ◽  
Jing Hong Song ◽  
Xiao Nv Li
Keyword(s):  
Excited States ◽  
Cross Sections ◽  
Fluorescence Spectra ◽  
Room Temperature ◽  
Transition Probabilities ◽  
Radiative Transition ◽  
Transparent Ceramic ◽  
Ofelt Theory ◽  
Radiation Trapping ◽  
Intensity Parameters

In this paper, we evaluated the spectra parameters of Er3+.The absorption spectra of Er3+:CaF2transparent ceramic was measured at room temperature (RT). Based on the Judd–Ofelt theory, the intensity parameters were Ω2= 5.02×10−20cm2, Ω4= 3.40×10−20cm2and Ω6= 0.38×10−20cm2, and then the values of the radiative transition probabilities, radiative lifetimes and integrated emission cross-sections of excited states were calculated. Full width at half maximum (FWHM) of the fluorescence spectra for4I13/2→4I15/2transition was investigated, being 17nm. The decay time was found to be 24.3ms, which is longer than the theoretically calculated value indicating a radiation trapping effect in this work.

Quenching of CO(B1Σ+,υ=0)by He,Ne,Ar,H2and D2

1973 ◽  
Vol 28 (5) ◽  
pp. 717-724 ◽  
Author(s):  
F. J. Comes ◽  
E. H. Fink
Keyword(s):  
Cross Sections ◽  
Transition Probabilities ◽  
Radiative Lifetime ◽  
Radiative Transition ◽  
Experimental Conditions ◽  
Steady State Fluorescence ◽  
Resonance Band ◽  
Straight Lines ◽  
Effective Collision ◽  
Sample Pressure

Excitation of CO molecules into the lowest vibrational level of the B1Σ+ electronic state by absorption of the (B 1Σ+υ′=0 →X 1Σ+ ,υ′′=0) resonance band at 1150 Å has been studied under various experimental conditions by observing the steady state fluorescence of the (B 1Σ+→A1Π) Angstrom bands. Stern-Volmer plots of the fluorescence intensities at the addition of various foreign gases yielded straight lines whose slopes k̃qм = kqм · τeff were strongly dependent on the CO sample pressure. This effect was found to be due to changes of the effective radiative lifetime of the B 1Σ+υ′=0 because of resonance trapping of the (0,0) band of the (B → X) fluorescence. The CO(B 1Σ+υ′=0) molecules are found to be quenched by He, Ne, Ar, H2 and D2 with effective collision cross sections of 0.23, 0.48, 22.4, 10.7, and 11.4 Å2, respectively, at 298 °K. In addition, an approximate value for the ratio ABA/ (ABA+ABX)of the radiative transition probabilities of the (B → A) and (B → X) transitions could be derived from the measurements.

scholarly journals New Radiative Atomic Data

2005 ◽  
Vol 13 ◽  
pp. 668-671
Author(s):  
Sultana N. Nahar
Keyword(s):  
Cross Sections ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Radiative Transition ◽  
Dielectronic Recombination ◽  
Oscillator Strengths ◽  
Rate Coefficients ◽  
Atomic Data ◽  
Self Consistent ◽  
Ion Recombination

AbstractLarge amount of new radiative atomic data for I) energy levels, II) oscillator strengths (f), line strengths (S), radiative transition probabilities (A), III) photoioniztion cross sections (σPI) – total and level-specific, and IV) unified total and level-specific electron-ion recombination rate coefficients, αR, including radiative and dielectronic recombination (RR and DR) are reported for various astrophysical applications. Most of the data are with fine structure. These data are not yet available from any databases. Photoionization and recombination data are self-consistent, using the same wave-function for both processes.

scholarly journals Benchmarking Current Capabilities for the Generation of Excitation and Photoionisation Atomic Data

2018 ◽  
Author(s):  
Catherine Ramsbottom ◽  
Connor Ballance ◽  
Ryan Smyth ◽  
Andrew Conroy ◽  
Luis Fernández-Menchero ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Cross Sections ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Radiative Transition ◽  
Atomic Data ◽  
High Quality ◽  
Astronomical Instruments ◽  
First Time ◽  
Line Strengths

The spectra currently emerging from modern ground- and space-based astronomical instruments are of exceptionally high quality and resolution. To meaningfully analyse these spectra researchers utilise complex modelling codes to replicate the observations. The main inputs to these codes are atomic data such as excitation and photoionisation cross sections as well as radiative transition probabilities, energy levels and line strengths. In this publication the current capabilities of the numerical methods and computer packages used in the generation of these data are discussed. Particular emphasis is given to Fe-peak species and the heavy systems of tungsten and molybdenum. Some of the results presented to highlight certain issues and/or advances have already been published in the literature, while other sections present, for the first time, new recently evaluated atomic data.

New Atomic Data for Astronomy: An Introductory Review

1995 ◽  
Vol 10 ◽  
pp. 570-571
Author(s):  
M.J. Seaton
Keyword(s):  
Line Profile ◽  
Cross Sections ◽  
Transition Probabilities ◽  
Energy Levels ◽  
Experimental Studies ◽  
Theoretical Work ◽  
Radiative Transition ◽  
Rate Coefficients ◽  
Atomic Data ◽  
Collisional Rate Coefficients

Astronomers require the following basic atomic data: energy levels and wavelengths’, radiative transition probabilities; cross sections for photo-ionisation and for collisional processes; and line profile parameters. They also require processed data such as: level populations; opacities; radiation forces; line emissivities; and collisional rate-coefficients.Many of the data used by astronomers come from theoretical work. Experimental work is of importance in determining accurate wavelengths, in providing essential checks on theory for radiative probabilities and collision rates, and in the determination of line-profile parameters. Experimental studies are particularly important for processes of collisional ionisation.

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