Carbon Dioxide Band Research Articles

Refractive Index of Silver Chloride for Visible and Infra-Red Radiant Energy*

The refractive indices of a 31° prism of silver chloride were measured at 30 wave-lengths at a constant room temperature of 23.9°C, from 0.578 to 20.6μ by use of a minimum-deviation spectrometer and a Perkin-Elmer infra-red spectrometer equipped with a calibrated screw for operation of the Littrow mirror. A cadmium-mercury lamp was the source from 1 to 2μ. From 2 to 20μ a Globar was used as the source with various Baird’s reflection interference filters and the absorption bands of carbon dioxide, carbon disulfide, water, methylcyclohexane, polystyrene, trichlorobenzene, and chlorobenzotrifluoride for the identification of wave-lengths. In the visible region two prisms, one pressed and polished, the other sawed and lapped, were used and the results compared. The sensitivity of index to temperature is approximately −6.1 × 10−5 per centigrade degree for wave-length 0.610μ.

Line Intensities and Absorption for the 15-Micron Carbon Dioxide Band

Thorndike's value of 560×1010 cycles per centimeter-atmosphere for the total intensity of the 15-micron carbon dioxide band is used to calculate the line intensities at one atmosphere and 300°K. Calculation of absorption results in good agreement with published absorption curves by Martin and Barker. Absorption for 203 millibars and 218°K is recalculated, correcting previous errors and using better approximations.

Carbon Dioxide in the Infra-Red Solar Spectrum

Wave-length measurements are given for lines in thirteen vibration-rotation bands of carbon dioxide observed between 1.5\ensuremath{\mu} and 2.1\ensuremath{\mu} in the infra-red solar spectrum and in the laboratory. The observations were made with the McGregor spectrometer and Cashman cell of the McMath-Hulbert Observatory. Among the thirteen bands, seven originate from the ground state and two from the first excited state of ${\mathrm{C}}^{12}$${\mathrm{O}}_{2}^{16}$. The remaining four are identified with ground state transitions in the isotopic molecules ${\mathrm{C}}^{13}$${\mathrm{O}}_{2}^{16}$ and ${\mathrm{C}}^{12}$${\mathrm{O}}^{16}$${\mathrm{O}}^{18}$. The rotational constants ${\ensuremath{\alpha}}_{1}$, ${\ensuremath{\alpha}}_{2}$, and ${\ensuremath{\alpha}}_{3}$ have been determined from analysis of the rotational structures. The mean value found for ${B}_{000}$ is 0.3906 ${\mathrm{cm}}^{\ensuremath{-}1}$ and for the equilibrium position ${B}_{e}=0.3920$ ${\mathrm{cm}}^{\ensuremath{-}1}$.

Resolution of the carbon dioxide bands at 1.6 microns.

Resolution of the carbon dioxide bands at 1.6 microns.

The Experimental Determination of the Intensities of Infra-Red Absorption Bands. III. Carbon Dioxide, Methane, and Ethane

The absolute intensities of the chief infra-red absorption bands of carbon dioxide, methane, and ethane have been determined experimentally to be (in cycles per centimeter at N.T.P.): Carbon dioxideMethaneEthane670 cm−1 band:560×10101306 cm−1 band:450×1010 820 cm−1 band: 73×10102350 cm−1 band:8600×10103020 cm−1 band:900×10101450 cm−1 bands: 230×10102950 cm−1 bands:2200×1010These results are in satisfactory agreement with available data on infra-red dispersion and atomic polarization. They may be interpreted in terms of dipole moments, μ′, of bonds between vibrating atoms, and their rates of change with internuclear distance, ∂μ′/∂r. When this is done for the CH bond, however, unexpected variations in these quantities are found for the different vibrations and molecules studied. The average values are about μ′=0.4×10−18, ∂μ′/∂r=±0.6×10−10. For the CO bond the values are considerably larger.

The Grating Infrared Solar Spectrum. III. Rotational Structure of the Carbon Dioxide (CO_{2}) Band ν_{2} at 13.9 μ.

view Abstract Citations (6) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Grating Infrared Solar Spectrum. III. Rotational Structure of the Carbon Dioxide (CO_{2}) Band ν_{2} at 13.9 μ. Adel, Arthur Abstract The rotational structure in the positive branch of the carbon dioxide band [(v1, 2v2) - p2], centered at 13.9 j~, is extensively developed in the solar spectrum between 13.9 ~ and 13.0 ~. Rotational levels through quantum number J = 64 are represented. The rotation lines are satisfactorily ordered by the expression vcm-~ = 720.71 + 0.789 N - 0.00051 N2, where N is the ordinal number of the line. The equilibrium moment of inertia of the CO2 molecule deduced from the observations is A = 70.8 X i~4° gm cm2, in excellent agreement with laboratory determinations and with the value obtained from the CO2 bands in the spectrum of Venus. The low transmission of the terrestrial atmosphere between the ailternative long wave-length limits of transmission ~ j~ and ~ ~ is evident in the grating solar spectrum of this region Publication: The Astrophysical Journal Pub Date: September 1941 DOI: 10.1086/144340 Bibcode: 1941ApJ....94..375A full text sources ADS | Related Materials (5) Part 1: 1941ApJ....93..506A Part 2: 1941ApJ....93..509A Part 4: 1941ApJ....94..379A Part 5: 1941ApJ....94..449A Part 6: 1941ApJ....94..451A

The Importance of Certain Carbon Dioxide Bands in the Temperature Radiation from Venus.

The Importance of Certain Carbon Dioxide Bands in the Temperature Radiation from Venus.

Polarization and Intensity Measurements in the Raman Spectrum of Carbon Dioxide

The relative intensities and the depolarizations (for unpolarized incident light) of the two principal Raman bands of carbon dioxide have been measured. The following results were obtained: ${\ensuremath{\rho}}_{1286}=0.18, {\ensuremath{\rho}}_{1389}=0.14, \frac{{I}_{1286}}{{I}_{1389}}=0.61.$

The Excitation Potential of the λ 2883 and λ 2895 Bands of Carbon Dioxide

The Excitation Potential of the λ 2883 and λ 2895 Bands of Carbon Dioxide

New Absorption Bands of Ammonia, Methyl Bromide, Methyl Iodide and Carbon Dioxide in the Infrared Spectrum

Work done with the recording spectrometer at the University of Michigan has shown near the wave-length 16.1\ensuremath{\mu} an absorption band of ammonia not hitherto observed in detail, and bands due to methyl bromide and methyl iodide, near wave-lengths 16.4\ensuremath{\mu} and 18.8\ensuremath{\mu} respectively. It has also shown the strong absorption band due to carbon dioxide near 15\ensuremath{\mu} to be more complex and extensive than has previously been indicated.

The Radiation from Explosions of Carbon Monoxide and Oxygen to which Hydrogen has been added

THE speed of explosion of mixtures of carbon monoxide and oxygen is accelerated by the addition of water or substances containing hydrogen, as was shown by Dixon. The acceleration of the speed is invariably accompanied by a reduction in the emission of radiant energy and vice versa (Garner and Johnson, Phil. Mag., 3, 97; 1927). The radiant energy emitted from these explosions consists mainly of two bands with maxima at 2.8μ and 4.4μ, which are the emission and absorption bands of carbon dioxide. The emitters of this radiation are the molecules of carbon dioxide which have been set in vibration and rotation by the chemical energy liberated during the explosion.

Emission and Absorption Bands of Carbon Dioxide in the Infrared

The absorption spectrum produced by a 12 cm cell of C${\mathrm{O}}_{2}$ gas, and the Bunsen flame emission spectrum, to ${3}_{\ensuremath{\mu}}$ were recorded by means of a new self-registering infrared quartz prism spectrograph of an auto-collimation type. A new weak absorption band was found at ${2.02}_{\ensuremath{\mu}}$ which forms a linear, though not a harmonic, frequency series with known bands at ${2.73}_{\ensuremath{\mu}}$ and ${4.25}_{\ensuremath{\mu}}$. This was identified with a ${1.99}_{\ensuremath{\mu}}$ flame emission band, which had been assigned by Paschen to water vapor. The ${2.7}_{\ensuremath{\mu}}$ emission region was widely resolved into two components of practically equal intensities, with maxima at ${2.58}_{\ensuremath{\mu}}$ and ${2.76}_{\ensuremath{\mu}}$, corresponding to maxima identified by Paschen with water vapor and C${\mathrm{O}}_{2}$, respectively. When the quartz prisms were replaced by a similar rock salt pair the ${4.4}_{\ensuremath{\mu}}$ emission occurred as a nearly symmetrical band, although Barker's measurements with high dispersion showed it to be double. Calculations of the Bunsen flame temperature from his observed separations gave 2000\ifmmode^\circ\else\textdegree\fi{} K, in rough agreement with previous pyrometer determinations.