Absorption cross-sections of atmospheric gases for use in aeronomy

1969 ◽  
Vol 47 (10) ◽  
pp. 1823-1834 ◽  
Author(s):  
Robert E. Huffman
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Emission Lines ◽  
Current Status ◽  
Absorption Cross ◽  
Atmospheric Gases ◽  
Ionization Cross ◽  
Atmospheric Absorption ◽  
Ionization Cross Sections

The current status of absorption cross-section measurements for aeronomic use is reviewed. Recommended values for the gases O2, N2, O, and O3 are given at wavelengths where there is strong atmospheric absorption in the 3500–10 Å region. A table of absorption and ionization cross-sections at important solar emission lines is given. The problem of insufficient resolution at some wavelengths is discussed, and information on photolysis products is given where available.

scholarly journals Ultraviolet Absorption Cross-Sections of Ammonia at Elevated Temperatures for Nonintrusive Quantitative Detection in Combustion Environments

2021 ◽  
pp. 000370282199044
Author(s):  
Wubin Weng ◽  
Shen Li ◽  
Marcus Aldén ◽  
Zhongshan Li
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Elevated Temperatures ◽  
Uv Absorption ◽  
Energy Utilization ◽  
Quantitative Detection ◽  
Absorption Cross ◽  
Hot Gas

Ammonia (NH3) is regarded as an important nitrogen oxides (NOx) precursor and also as an effective reductant for NOx removal in energy utilization through combustion, and it has recently become an attractive non-carbon alternative fuel. To have a better understanding of thermochemical properties of NH3, accurate in situ detection of NH3 in high temperature environments is desirable. Ultraviolet (UV) absorption spectroscopy is a feasible technique. To achieve quantitative measurements, spectrally resolved UV absorption cross-sections of NH3 in hot gas environments at different temperatures from 295 K to 590 K were experimentally measured for the first time. Based on the experimental results, vibrational constants of NH3 were determined and used for the calculation of the absorption cross-section of NH3 at high temperatures above 590 K using the PGOPHER software. The investigated UV spectra covered the range of wavelengths from 190 nm to 230 nm, where spectral structures of the [Formula: see text] transition of NH3 in the umbrella bending mode, v2, were recognized. The absorption cross-section was found to decrease at higher temperatures. For example, the absorption cross-section peak of the (6, 0) vibrational band of NH3 decreases from ∼2 × 10−17 to ∼0.5 × 10−17 cm2/molecule with the increase of temperature from 295 K to 1570 K. Using the obtained absorption cross-section, in situ nonintrusive quantification of NH3 in different hot gas environments was achieved with a detection limit varying from below 10 parts per million (ppm) to around 200 ppm as temperature increased from 295 K to 1570 K. The quantitative measurement was applied to an experimental investigation of NH3 combustion process. The concentrations of NH3 and nitric oxide (NO) in the post flame zone of NH3–methane (CH4)–air premixed flames at different equivalence ratios were measured.

scholarly journals Determination of the absorption cross-sections of higher order iodine oxides at 355 nm and 532 nm

2020 ◽  
Author(s):  
Thomas R. Lewis ◽  
Juan Carlos Gómez Martin ◽  
Mark A. Blitz ◽  
Carlos A. Cuevas ◽  
John M. C. Plane ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Atmospheric Chemistry ◽  
Absorption Cross Section ◽  
Absorption Cross ◽  
Time Resolved ◽  
Flight Mass Spectrometry ◽  
Iodine Oxides ◽  
Photo Ionization

Abstract. Iodine oxides (IxOy) play an important role in the atmospheric chemistry of iodine. They are initiators of new particle formation events in the coastal and polar boundary layer and act as iodine reservoirs in tropospheric ozone-depleting chemical cycles. Despite the importance of the aforementioned processes, the photochemistry of these molecules has not been studied in detail previously. Here, we report the first determination of the absorption cross sections of IxOy, x = 2, 3, 5, y = 1–12 at λ = 355 nm by combining pulsed laser photolysis of I2/O3 gas mixtures in air with time-resolved photo-ionization time-of-flight mass spectrometry, using NO2 actinometry for signal calibration. The oxides selected for absorption cross section determinations are those presenting the strongest signals in the mass spectra, where signals containing 4 iodine atoms are absent. The method is validated by measuring the absorption cross section of IO at 355 nm, σ355 nm, IO = (1.2 ± 0.1) ×  10–18 cm2, which is found to be in good agreement with the most recent literature. The results obtained are: σ355 nm, I2O3 

Cross Section Ratios for the Electron Impact Production of Singly and Multiply Ionized Rare Gas Ions

1978 ◽  
Vol 33 (9) ◽  
pp. 1111-1113 ◽  
Author(s):  
F. Egger ◽  
T. D. Mark
Keyword(s):  
Electron Impact ◽  
Cross Section ◽  
Mass Spectrometer ◽  
Cross Sections ◽  
Impact Ionization ◽  
Rare Gas ◽  
Ionization Cross ◽  
Single Ionization ◽  
Multiple Ionization ◽  
Ionization Cross Sections

Electron impact ionization of He, Ne, Ar, Kr and Xe has been studied with a double focussing mass spectrometer Varian MAT CH5. Ratios of various multiple ionization cross sections with respect to single ionization cross sections for He, Ne, Ar, Kr and Xe at electron energies of 50, 100 and 150eV are given. These cross section ratios are com­pared with previous determinations.

scholarly journals Determination of the absorption cross sections of higher-order iodine oxides at 355 and 532 nm

2020 ◽  
Vol 20 (18) ◽  
pp. 10865-10887
Author(s):  
Thomas R. Lewis ◽  
Juan Carlos Gómez Martín ◽  
Mark A. Blitz ◽  
Carlos A. Cuevas ◽  
John M. C. Plane ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Atmospheric Chemistry ◽  
Absorption Cross Section ◽  
Particle Formation ◽  
Absorption Cross ◽  
Iodic Acid ◽  
Iodine Oxides ◽  
532 Nm

Abstract. Iodine oxides (IxOy) play an important role in the atmospheric chemistry of iodine. They are initiators of new particle formation events in the coastal and polar boundary layers and act as iodine reservoirs in tropospheric ozone-depleting chemical cycles. Despite the importance of the aforementioned processes, the photochemistry of these molecules has not been studied in detail previously. Here, we report the first determination of the absorption cross sections of IxOy, x=2, 3, 5, y=1–12 at λ=355 nm by combining pulsed laser photolysis of I2∕O3 gas mixtures in air with time-resolved photo-ionization time-of-flight mass spectrometry, using NO2 actinometry for signal calibration. The oxides selected for absorption cross-section determinations are those presenting the strongest signals in the mass spectra, where signals containing four iodine atoms are absent. The method is validated by measuring the absorption cross section of IO at 355 nm, σ355nm,IO= (1.2±0.1) ×10-18 cm2, which is found to be in good agreement with the most recent literature. The results obtained are σ355nm,I2O3<5×10-19 cm2 molec.−1, σ355nm,I2O4= (3.9±1.2)×10-18 cm2 molec.−1, σ355nm,I3O6= (6.1±1.6)×10-18 cm2 molec.−1, σ355nm,I3O7= (5.3±1.4)×10-18 cm2 molec.−1, and σ355nm,I5O12= (9.8±1.0)×10-18 cm2 molec.−1. Photodepletion at λ=532 nm was only observed for OIO, which enabled determination of upper limits for the absorption cross sections of IxOy at 532 nm using OIO as an actinometer. These measurements are supplemented with ab initio calculations of electronic spectra in order to estimate atmospheric photolysis rates J(IxOy). Our results confirm a high J(IxOy) scenario where IxOy is efficiently removed during daytime, implying enhanced iodine-driven ozone depletion and hindering iodine particle formation. Possible I2O3 and I2O4 photolysis products are discussed, including IO3, which may be a precursor to iodic acid (HIO3) in the presence of HO2.

scholarly journals Direct and Dissociative Ionization Cross Section of Oxygen Molecule from Threshold to 10 KeV

2019 ◽  
Vol 8 (6S3) ◽  
pp. 1365-1368
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ionization Cross Section ◽  
Threshold Energy ◽  
Theoretical Data ◽  
Oxygen Molecule ◽  
Dissociative Ionization ◽  
Ionization Cross ◽  
Section Data ◽  
Ionization Cross Sections

Due to abundant applications of ionization in various fields of applied sciences, it’s desirable to calculate absolute ionization cross sections of various atoms or molecules. In this literature, we have calculated the absolute direct and dissociative ionization cross sections of the oxygen molecule from threshold energy to 10,000 eV by using revisited Jain-Khare semi-empirical approach. In this literature, the total direct and absolute ionization cross section data have compared with easily available experimental and/or theoretical data. The present results give a better account for the ionization cross sections up to higher incident electron energies.

Alkyl-triphenylamine end-capped triazines with AIE and large two-photon absorption cross-sections for bioimaging

2014 ◽  
Vol 2 (31) ◽  
pp. 6353-6361 ◽  
Author(s):  
Yuting Gao ◽  
Yi Qu ◽  
Tao Jiang ◽  
Hao Zhang ◽  
Nannan He ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Two Photon Absorption ◽  
Two Photon

Three alkyl-triphenylamine end-capped triazines (ATT-(1–3)) with AIE were synthesized, and the two-photon absorption cross section of ATT-3 was 10 003 GM.

scholarly journals Temperature dependent ozone absorption cross section spectra measured with the GOME-2 FM3 spectrometer and first application in satellite retrievals

2012 ◽  
Vol 5 (5) ◽  
pp. 7983-8015 ◽  
Author(s):  
W. Chehade ◽  
B. Gür ◽  
P. Spietz ◽  
V. Gorshelev ◽  
A. Serdyuchenko ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Gas Flow ◽  
Absolute Cross Section ◽  
Absorption Cross ◽  
Atmospheric Conditions ◽  
Section Data ◽  
Laboratory Setup ◽  
Ozone Column

Abstract. The Global Ozone Monitoring Experiment (GOME-2) Flight Model (FM) absorption cross section spectra of ozone were measured under representative atmospheric conditions in the laboratory setup at temperatures between 203 K and 293 K in the wavelength range of 230–790 nm at a medium spectral resolution of 0.24 to 0.54 nm. Since the exact ozone amounts were unknown in the gas flow system used, the measured ozone cross sections were required to be scaled to absolute cross section units using published literature data. The Hartley, Huggins and Chappuis bands were recorded simultaneously and their temperature dependence is in good agreement with previous studies (strong temperature effect in the Huggins band and weak in the Hartley and Chappuis bands). The overall agreement of the GOME-2 FM cross sections with the literature data is well within 3%. The total ozone column retrieved from the GOME-2/MetOp-A satellite using the new cross section data is within 1% compared to the ozone amounts retrieved routinely from GOME-2.

scholarly journals Revised temperature dependent ozone absorption cross section spectra (Bogumil et al.) measured with the sciamachy satellite spectrometer

2013 ◽  
Vol 6 (2) ◽  
pp. 2449-2481 ◽  
Author(s):  
W. Chehade ◽  
V. Gorshelev ◽  
A. Serdyuchenko ◽  
J. P. Burrows ◽  
M. Weber
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Total Ozone ◽  
Published Data ◽  
Absorption Cross ◽  
Atmospheric Conditions ◽  
Cross Section Data ◽  
Ozone Absorption ◽  
Section Data

Abstract. Ozone absorption cross section spectra and other trace gases had been measured using the Scanning Imaging Absorption spectroMeter for Atmospheric ChartograpHY (SCIAMACHY) satellite instrument at relevant atmospheric conditions. The measured cross sections were relative cross sections and were converted to absolute values using published data. Using the SCIAMACHY's FM cross sections as published by Bogumil et al. (2003) in the SCIAMACHY retrievals of total ozone leads to an overestimation in the total ozone by 5% compared to collocated GOME data. This work presents the procedures followed to correct the ozone cross section data as published in Bogumil et al. (2003) starting from original raw data (optical density spectra) from the original measurements. The revised data agrees well within 3% with other published ozone cross-sections and preserves the correct temperature dependence in the Hartley, Huggins, Chappuis and Wolf bands. SCIAMACHY's total ozone columns retrieved using the revised cross section data are shown to be within 1% compared to the ozone amounts retrieved routinely from SCIAMACHY.

scholarly journals On the total absorption cross-section of galaxies - II: The case of λ cosmologies and covering factor variation

1998 ◽  
pp. 3-7
Author(s):  
M.M. Cirkovic ◽  
S. Samurovic
Keyword(s):  
Cosmological Constant ◽  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Observational Cosmology ◽  
Total Absorption ◽  
Absorption Cross ◽  
Normal Galaxies ◽  
Previous Discussion ◽  
Inner Parts

In this work we expand the previous discussion of the plausibility of hypothesis of origin of the Ly? forest absorption systems in haloes of normal galaxies in connection with the HubbleDeepField (HDF) data. It is shown that simplistic approach to absorption cross-sections of galaxies with no luminosity scaling is in strong violation of empirical statistics up to redshift of z ? 3.5. Realistic variation of the covering factor in order to account for its increase in the inner parts of observed haloes leads to even bigger discrepancy. Cosmologies with finite cosmological constant are briefly discussed and compared to ? = 0 case. Ways to improve agreement with observational data are indicated. This problem is highly illustrative of the basic tenets of modern observational cosmology.

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