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 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.

scholarly journals MCSCF-CI Calculations of Radiative Transition Probabilities of PH and PD

1986 ◽  
Vol 41 (5) ◽  
pp. 719-723 ◽  
Author(s):  
J. Senekowitsch ◽  
P. Rosmus ◽  
H. J. Wemer ◽  
M. Larsson
Keyword(s):  
Transition Probabilities ◽  
Dipole Moments ◽  
Radiative Lifetime ◽  
Radiative Transition ◽  
Vibrational States ◽  
Electronic Transition Moment ◽  
Vibrational Ground State ◽  
Moment Functions ◽  
Highly Correlated ◽  
Ci Calculations

Potential energy, dipole moment, and electronic transition moment functions for the A 3Πand X3Σ- states of PH have been calculated from highly correlated electronic wavefunctions. The electric dipole moments in the vibrational ground state of PH are calculated to be 0.637 Debye (A 3Π) and 0.403 Debye (X3Σ-). The predicted rates of spontaneous emission between low lying vibrational states of the X state lie in the range of 46 to 109 sec-1 (PH) and 12 to 30 sec-1 (PD). The calculated radiative lifetime of the v' = 0 level in the A 3Π state of 400 ns is lower by about 10 percent than the most recent experimental value. The classical intersection of the 5Σ- and the A 3Πstate has been calculated to lie between v' = 2 and 3 with an expected uncertainty of about 500 cm−1, whereas the onset of the rotationally dependent predissociation lies at v' = 0, J' = 11.

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.

scholarly journals Optical Transition Probabilities of Er3+Ions in ErBa3B9O18Crystal

2015 ◽  
Vol 2015 ◽  
pp. 1-4
Author(s):  
Ming He ◽  
Tiezheng Liu ◽  
Junling Xiu ◽  
Yuanguang Tang ◽  
Zhihua Zhang
Keyword(s):  
Optical Absorption ◽  
Cross Sections ◽  
Transition Probabilities ◽  
Optical Transition ◽  
Radiative Lifetime ◽  
Absorption Data ◽  
Birefringent Crystal ◽  
Intensity Parameters ◽  
Thin Disk Laser ◽  
Er Doped

The optical absorption and emission intensity of luminescent and birefringent crystal ErBa3B9O18were examined from optical absorption data based on Judd-Ofelt theory. The three intensity parametersΩt(t=2,4,6) are 3.10 × 10−20, 0.87 × 10−20, and 1.80 × 10−20 cm2, respectively. From the obtained intensity parameters, the radiative probabilitiesAr, radiative lifetimeτf, fluorescence branching ratiosβc, and integrated emission cross sections∑have been calculated. In comparison with other Er-doped luminescent crystals, ErBa3B9O18may find application in thin disk laser.

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.

Judd-Ofelt Analysis of a Dendrtic Type Europium Complex/Silicone Rubber

2011 ◽  
Vol 233-235 ◽  
pp. 1227-1230 ◽  
Author(s):  
Hao Liang ◽  
Fang Xie
Keyword(s):  
Cross Sections ◽  
Silicone Rubber ◽  
Radiative Lifetime ◽  
Radiative Transition ◽  
Optical Devices ◽  
Europium Complex ◽  
Stimulated Emission ◽  
Ofelt Theory ◽  
Intensity Parameters ◽  
Radiative Transition Rate

A dendritic type europium complex/silicone rubber has been prepared. According to the luminescence spectrum, the Judd-Ofelt theory was adopted to calculate the intensity parameters Ω2and Ω4. The total radiative transition rate (640.1 s-1), radiative lifetime (1.562 ms) and the stimulated emission cross-sections (46.19×10-22cm2) of the5D0exciting state have been evaluated. Analysis reveals that the europium (III) chelating polymer is promising for use in optical devices.

scholarly journals Synthesis, Structural and Luminescence Studies of Europium Doped Borate Glasses

2020 ◽  
Vol 9 (1) ◽  
pp. 9-16
Author(s):  
V L Usharani ◽  
B Eraiah
Keyword(s):  
Cross Sections ◽  
Transition Probabilities ◽  
Emission Cross Section ◽  
Radiative Lifetime ◽  
Emission Spectra ◽  
Optical Gain ◽  
Stimulated Emission ◽  
Melt Quenching ◽  
Fibre Amplifiers ◽  
Quenching Method

Different concentration of (0.1, 0.2, 0.3, 0.4, 0.5, 1.0 & 1.5) mol% of europium doped lead borate lithium glasses were prepared by melt quenching method. The properties of thermal, photoluminescence & structural were analyzed using DTA, FTIR and emission spectra. Emission spectra was used to evaluate the Judd-Ofelt (JO) parameters. Radiative parameters like stimulated emission cross-sections (σe), effective band width (∆λeff), transition probabilities (A), optical gain bandwidths (σe x ∆λeff), radiative lifetime (τrad) and optical gain (σe x τrad) values were evaluated for the transition 5D0→7Fj (j=1, 2, 3 and 4) of Eu3+ ions. The outcome of transition 5D0→7F4 at its highest value of branching ratios and stimulated emission cross-section are evaluated with the literature. Hence we can could the prepared host glass doped with Eu3+ ions are good fibre amplifiers and it can be used as a red laser.

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.

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