Absorption cross-sections in the vacuum ultra-violet - II. The Schumann-Runge bands of oxygen (2000 to 1750Å)

1954 ◽  
Vol 226 (1167) ◽  
pp. 509-521 ◽  
Keyword(s):  
Oscillator Strength ◽  
Cross Sections ◽  
Ultra Violet ◽  
Oscillator Strengths ◽  
Dissociation Limit ◽  
Absorption Cross ◽  
The Cross ◽  
Vibrational Transitions ◽  
Vacuum Ultra Violet ◽  
The Continuum

Absorption cross-sections for oxygen in the region 2000 to 1750 Å, corresponding to the process O 2 X 3 Σ - g + hv → O 2 B 3 Σ - u have been measured. The oscillator strengths for the vibrational transitions have been calculated from these results. The total oscillator strength (including the continuum) is found to be 0·259. The cross-sections for intermolecular collisions causing deactivation of the upper state are found and analyzed. The (0-19) and (0-20) members of the system are observed, and the dissociation limit found to be 57140 ± 20 K .

Absorption cross-sections in the vacuum ultra-violet. - I. Continuous absorption of oxygen (1800 to 1300 Å)

1953 ◽  
Vol 220 (1140) ◽  
pp. 61-70 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ultra Violet ◽  
Absorption Cross ◽  
Absorption Spectrophotometry ◽  
Maximum Value ◽  
Continuous Absorption ◽  
The Cross ◽  
Quantitative Absorption ◽  
Vacuum Ultra Violet

Absorption cross-sections for oxygen in the region 1670 to 1360 Å, corresponding to the process O 2 3 Ʃ g - + hv → O( 3 P ) + O( 1 D ), have been measured. The cross-section has a maximum value of 1⋅81 x 10 -17 cm 2 at 1450 Å and falls to half-value at 1567 and 1370 Å. The paper includes an account of technical methods of quantitative absorption spectrophotometry in this part of the vacuum ultra- violet.

Absorption cross-sections in the vacuum ultra-violet III. Methane

1955 ◽  
Vol 229 (1176) ◽  
pp. 44-62 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Wave Length ◽  
Ultra Violet ◽  
Photoionization Cross Section ◽  
Absorption Cross ◽  
Continuous Absorption ◽  
Length Range ◽  
Photo Ionization ◽  
Vacuum Ultra Violet

Cross-sections for the continuous absorption of radiation by methane in the wave-length range 1600 to 350A have been measured. The absorption is analyzed so as to distinguish between absorption leading to photo-dissociation processes and absorption due to photoionization. The main photo-ionization process is CH 4 +hv->CH 4 + -e - , and the photoionization cross-section is measured for free electron energies from 0 to about 20 eV. Little evidence is found for processes such as CH 4 + hv-> CH 2 + H+e - The results are compared with calculations by Dalgamo. The paper includes an account of the technique of photographic spectrophotometry in the region 1100 to 200A.

Dipole oscillator strength distributions and properties for SO2, CS2, and OCS

1985 ◽  
Vol 63 (3) ◽  
pp. 417-427 ◽  
Author(s):  
Ashok Kumar ◽  
William J. Meath
Keyword(s):  
Oscillator Strength ◽  
Cross Sections ◽  
Ground State ◽  
Strength Properties ◽  
Oscillator Strengths ◽  
Sum Rule ◽  
Strength Data ◽  
Dilute Gases ◽  
Dipole Oscillator ◽  
Strength Distributions

Dipole oscillator strength distributions have been constructed and used to evaluate integrated oscillator strengths, and a variety of dipole oscillator strength properties, for ground state SO2, CS2, and OCS. Each distribution has been constructed by using experimental and theoretical photoabsorption cross sections and by subjecting the resulting dipole oscillator strength data to constraints provided by the Thomas–Reiche–Kuhn sum rule and molar refractivity data for the relevant dilute gases. The discussion includes graphical presentations of how various spectral regions of the dipole oscillator strength distributions contribute to the more important dipole properties.

Absorption Cross Sections of O2(a1Δg) and O2(X3Σg−) in the Region from 1087 to 1700 Å

1975 ◽  
Vol 53 (19) ◽  
pp. 1845-1852 ◽  
Author(s):  
S. Ogawa ◽  
M. Ogawa
Keyword(s):  
Metastable State ◽  
Cross Sections ◽  
Ground State ◽  
Experimental Error ◽  
Wavelength Region ◽  
Absorption Cross ◽  
Band Structures ◽  
The Cross

An attempt has been made to measure the absorption cross sections of O2 in the metastable state a1Δg from 1087 to 1700 Å. The absorption is measurable (σa ≥ 3 × 10−19 cm2) from around 1500 Å towards shorter wavelengths. Many band structures overlaying various continua have been seen. Absorption cross sections of O2 in the ground state X3Σg− also have been measured in the same wavelength region and our results agree with previously published values within experimental error. The cross sections of O2(a1Δg) are generally larger than those of O2(X3Σg−) below 1290 Å except at the wavelengths of a few strong bands of O2(X3Σg−).

Dipole oscillator strength distributions and related properties for ethylene, propene and 1-butene

1983 ◽  
Vol 61 (7) ◽  
pp. 1027-1034 ◽  
Author(s):  
B. L. Jhanwar ◽  
William J. Meath ◽  
J. C. F. MacDonald
Keyword(s):  
Oscillator Strength ◽  
Cross Sections ◽  
Ground State ◽  
Oscillator Strengths ◽  
Detailed Model ◽  
Sum Rule ◽  
Strength Data ◽  
Dilute Gases ◽  
Dipole Oscillator ◽  
Strength Distributions

Dipole oscillator strength distributions (DOSDs) have been constructed for ground state ethylene, propene, and 1-butene. Each DOSD is constructed by using available experimental and theoretical photoabsorption cross sections and by constraining the resulting dipole oscillator strength data to satisfy the Thomas – Reiche–Kuhn sum rule and molar refractivity constraints. The latter were obtained from experimental refractive index measurements of relevant dilute gases. The recommended DOSDs, and the values of integrated "band" oscillator strengths, and the dipole oscillator strength sums Sk and Lk (for a variety of k values) obtained from them, are reported. The discussion includes an analysis of the reliability of the results using 1-butene as a detailed model.

Dipole oscillator strength distributions and properties for methanol, ethanol, and n-propanol

1984 ◽  
Vol 62 (2) ◽  
pp. 373-381 ◽  
Author(s):  
B. L. Jhanwar ◽  
William J. Meath
Keyword(s):  
Oscillator Strength ◽  
Cross Sections ◽  
Ground State ◽  
Oscillator Strengths ◽  
Sum Rule ◽  
Strength Data ◽  
Molar Refractivity ◽  
Dipole Oscillator ◽  
Strength Distributions

Dipole oscillator strength distributions (DOSDs) have been constructed for ground state methanol, ethanol, and n-propanol and used to evaluate integrated ("band") oscillator strengths and the dipole oscillator strength sums Sk and Lk (for a variety of k values) for these molecules. Each DOSD is constructed by using available experimental and theoretical photoabsorption cross sections and by constraining the resulting dipole oscillator strength data to satisfy the Thomas–Reiche–Kuhn sum rule and molar refractivity constraints. The discussion includes an analysis of the reliability of the results.

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