Absorption Cross Sections of Carbon Dioxide and Carbon Monoxide in the Vacuum Ultraviolet

1955 ◽  
Vol 23 (9) ◽  
pp. 1625-1628 ◽  
Author(s):  
H. Sun ◽  
G. L. Weissler
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Cross Sections ◽  
Vacuum Ultraviolet ◽  
Absorption Cross

scholarly journals Strong spectral dependence of light absorption by organic carbon particles formed by propane combustion

2006 ◽  
Vol 6 (10) ◽  
pp. 2981-2990 ◽  
Author(s):  
M. Schnaiter ◽  
M. Gimmler ◽  
I. Llamas ◽  
C. Linke ◽  
C. Jäger ◽  
...  
Keyword(s):  
Cross Sections ◽  
Vacuum Ultraviolet ◽  
Single Scattering ◽  
Absorption Cross ◽  
Propane Combustion ◽  
Tem Analysis ◽  
Carbon Particles ◽  
Angstrom Exponent ◽  
Ångström Exponent ◽  
Ångstrom Exponent

Abstract. We have measured the extinction and absorption cross sections of carbon particles emitted by a propane diffusion flame both in an aerosol chamber and on size-segregated samples deposited on optical windows. The absorption cross section, the single scattering albedo, and the Ångström exponent show drastic dependencies both on the C/O ratio and on the particle size. This is interpretated as being due to the appearance of nucleation modes of smaller organic particles at higher C/O ratios, which were detected by SMPS measurements and partially by TEM analysis. The spectral range of the validity of the absorption power-law (Ångström exponent) model is investigated by vacuum ultraviolet extinction measurements. These measurements give also indications for a preferentially aromatic nature of the OC component of the flame products.

Ultraviolet absorption cross-sections of hot carbon dioxide

2004 ◽  
Vol 399 (4-6) ◽  
pp. 490-495 ◽  
Author(s):  
Matthew A. Oehlschlaeger ◽  
David F. Davidson ◽  
Jay B. Jeffries ◽  
Ronald K. Hanson
Keyword(s):  
Carbon Dioxide ◽  
Cross Sections ◽  
Ultraviolet Absorption ◽  
Absorption Cross

scholarly journals VUV-absorption cross section of carbon dioxide from 150 to 800 K and applications to warm exoplanetary atmospheres

2018 ◽  
Vol 609 ◽  
pp. A34 ◽  
Author(s):  
O. Venot ◽  
Y. Bénilan ◽  
N. Fray ◽  
M.-C. Gazeau ◽  
F. Lefèvre ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
High Resolution ◽  
Cross Section ◽  
Wavelength Range ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Planetary Atmospheres ◽  
Temperature Dependency ◽  
Absorption Cross ◽  
The Continuum

Context. Most exoplanets detected so far have atmospheric temperatures significantly higher than 300 K. Often close to their star, they receive an intense UV photons flux that triggers important photodissociation processes. The temperature dependency of vacuum ultraviolet (VUV) absorption cross sections are poorly known, leading to an undefined uncertainty in atmospheric models. Similarly, data measured at low temperatures similar to those of the high atmosphere of Mars, Venus, and Titan are often lacking. Aims. Our aim is to quantify the temperature dependency of the VUV absorption cross sections of important molecules in planetary atmospheres. We want to provide high-resolution data at temperatures prevailing in these media, and a simple parameterisation of the absorption in order to simplify its use in photochemical models. This study focuses on carbon dioxide (CO2). Methods. We performed experimental measurements of CO2 absorption cross sections with synchrotron radiation for the wavelength range (115–200 nm). For longer wavelengths (195–230 nm), we used a deuterium lamp and a 1.5 m Jobin-Yvon spectrometer. We used these data in our one-dimensional (1D) thermo-photochemical model in order to study their impact on the predicted atmospheric compositions. Results. The VUV absorption cross section of CO2 increases with the temperature. The absorption we measured at 150 K seems to be close to the absorption of CO2 in the fundamental ground state. The absorption cross section can be separated into two parts: a continuum and a fine structure superimposed on the continuum. The variation in the continuum of absorption can be represented by the sum of three Gaussian functions. Using data at high temperature in thermo-photochemical models significantly modifies the abundance and the photodissociation rates of many species in addition to CO2, such as methane and ammonia. These deviations have an impact on synthetic transmission spectra, leading to variations of up to 5 ppm. Conclusions. We present a full set of high-resolution (Δλ = 0.03 nm) absorption cross sections of CO2 from 115 to 230 nm for temperatures ranging from 150 to 800 K. A parameterisation allows us to calculate the continuum of absorption in this wavelength range. Extrapolation at higher temperature has not been validated experimentally and therefore should be used with caution. Similar studies on other major species are necessary to improve our understanding of planetary atmospheres.

Inelastic scattering of high energy electrons by atmospheric gases

1969 ◽  
Vol 47 (10) ◽  
pp. 1733-1774 ◽  
Author(s):  
Edwin N. Lassettre
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Inelastic Scattering ◽  
Electron Impact ◽  
Cross Sections ◽  
High Energy ◽  
Oscillator Strengths ◽  
Atmospheric Gases ◽  
High Energy Electrons ◽  
Forbidden Transitions

Inelastic scattering of electrons by nitrogen, oxygen, carbon monoxide, carbon dioxide, water, argon, and helium is reviewed. Electron impact spectra at both high (less than 40 keV) and low (greater than 15 eV) kinetic energies are presented and discussed. Collision cross sections and generalized oscillator strengths are described, when data are available, and the connection with optical oscillator strengths is discussed. The limiting selection rules which hold in the excitation of atoms and molecules by electron impact are discussed and typical examples of forbidden transitions are described.

Vacuum ultraviolet absorption cross sections of SiH4, GeH4, Si2H6, and Si3H8

1986 ◽  
Vol 85 (9) ◽  
pp. 4867-4872 ◽  
Author(s):  
Uichi Itoh ◽  
Yasutake Toyoshima ◽  
Hideo Onuki ◽  
Nobuaki Washida ◽  
Toshio Ibuki
Keyword(s):  
Cross Sections ◽  
Vacuum Ultraviolet ◽  
Ultraviolet Absorption ◽  
Absorption Cross
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