The OH Meinel bands in the airglow—the radiative lifetime

1978 ◽  
Vol 56 (5) ◽  
pp. 581-586 ◽  
Author(s):  
E. J. Llewellyn ◽  
B. H. Long
Keyword(s):  
Rate Constants ◽  
Rotational Temperature ◽  
Radiative Lifetime ◽  
Rotational Relaxation ◽  
Vibrational Levels

A model of the rotational relaxation of an emitting population has been used to determine the rotational temperature of emitted spectra for the OH Meinel bands. It is shown that the calculated rotational temperatures for these spectra are consistent with laboratory observations of the hydrogen–ozone reaction if the radiative lifetime for the Meinel bands is short, [Formula: see text]The model is also used to infer the initial rotational populations of the OH vibrational levels excited in the hydrogen–ozone reaction. It has been found that these initial rotational populations may be described by rotational temperatures of 1940, 1230, and 760 K for the seventh, eighth, and ninth vibrational levels, respectively. It is also concluded that the rate constants for vibrational quenching will be increased from previously accepted values. The effect of a short radiative lifetime for airglow observations is also discussed.

Collisional Deactivation Rates of Electronically Excited Molecular Ions. II

1972 ◽  
Vol 50 (1) ◽  
pp. 1-7 ◽  
Author(s):  
G. I. Mackay ◽  
R. E. March
Keyword(s):  
Rate Constants ◽  
Radiative Lifetime ◽  
Molecular Ions ◽  
Deactivation Rate ◽  
Complete Knowledge ◽  
Induced Dipole ◽  
Excited Species ◽  
Vibrational Levels ◽  
Electronically Excited ◽  
Deactivation Rate Constant

Total deactivation rate constants have been determined for N2+(B2Σu+) and the (A2Πu) and (B2Σu+) states of CO2+ with a number of quenchers. The energy specific total deactivation rate constant is compared to the total radiative lifetime of the excited species. A particular novelty of the technique is that it does not require a complete knowledge of the formation modes for the excited species. The results are compared with theoretical values obtained from the ion-induced dipole model. Individual deactivation rate constants are presented for N2+(B2Σu+) ions in the v = 0, 1, and 2 vibrational levels quenched by N2, O2, H2, and CO2; and for the(A2Πu) and (B2Σu+) states of CO2+ quenched byCO2, N2, O2, NO, and H2. Charge transfer is the most probable mode of deactivation except in the CO2+–H2 reactions where H-atom abstraction is more probable.

scholarly journals State-to-state rotational relaxation rate constants for CO+Ne from IR–IR double-resonance experiments: Comparing theory to experiment

2004 ◽  
Vol 120 (16) ◽  
pp. 7483-7489 ◽  
Author(s):  
David A. Hostutler ◽  
Tony C. Smith ◽  
Gordon D. Hager ◽  
George C. McBane ◽  
Michael C. Heaven
Keyword(s):  
Relaxation Rate ◽  
Rate Constants ◽  
Double Resonance ◽  
Rotational Relaxation

Collisional Deactivation Rates of N2+ (B2Σu+)

1971 ◽  
Vol 49 (8) ◽  
pp. 1268-1271 ◽  
Author(s):  
G. I. Mackay ◽  
R. E. March
Keyword(s):  
Electron Beam ◽  
Charge Transfer ◽  
Rate Constants ◽  
Electron Beam Excitation ◽  
Vibrational Levels ◽  
Most Probable Mode ◽  
Electronically Excited ◽  
State Charge ◽  
Beam Excitation

Electron beam excitation of nitrogen was utilized to produce ions in the zeroth and first vibrational levels of the B2Σu+ state. The rate constants for the collisional deactivation of electronically excited N2+, for each of N2 and NO, were determined individually for the v′ = 0 and v′ = 1 vibrational levels of the N2+(B2Σu+) state. Charge transfer is the most probable mode of deactivation.

Analysis of auroral first negative bands

1987 ◽  
Vol 65 (9) ◽  
pp. 1119-1132 ◽  
Author(s):  
K. Henriksen ◽  
L. Veseth
Keyword(s):  
Electronic State ◽  
Least Squares Method ◽  
Rotational Temperature ◽  
Numerical Approach ◽  
Synthetic Spectrum ◽  
Particle Impact ◽  
Population Densities ◽  
Vibrational Levels ◽  
Rotational Part ◽  
E Region

An exact numerical approach is used to compute the rotational part of the line strengths (Hönl–London factors) for the [Formula: see text], [Formula: see text] transition (1NG bands). The computed Hönl–London factors enable a synthetic spectrum to be derived, which is then fitted as a final step to observed auroral [Formula: see text] 1NG bands by use of a least squares method. In this way we determine the population densities of the vibrational levels of the upper [Formula: see text] electronic state and, in addition, an average rotational temperature. Our results give clear evidence that the auroral [Formula: see text] 1NG bands are mainly generated by particle impact on neutral O2 molecules in their electronic and vibrational ground states, and that the bands are produced within the E region.

Vibrational energy distribution in HF formed by elimination from activated CH3CF3 and CH2CF2

1970 ◽  
Vol 48 (18) ◽  
pp. 2919-2930 ◽  
Author(s):  
P. N. Clough ◽  
J. C. Polanyi ◽  
R. T. Taguchi
Keyword(s):  
Rate Constants ◽  
Vibrational Energy ◽  
Flow System ◽  
Relative Rate ◽  
Elimination Reaction ◽  
Vibrationally Excited ◽  
Vibrational Levels ◽  
Relative Rate Constants ◽  
Fast Flow ◽  
Vibrational Energy Distribution

The combination–elimination reaction CH3 + CF3 → CH3CF3† → CH2CF2 + HF has been studied in a fast-flow system. Infrared chemiluminescence arising from the HF product has been observed from vibrational levels v = 1–4, and relative rate constants, k(v), have been obtained for HF formation in these levels. A study has also been made of the reaction CH2CF2 + Hg*(63P1) → CHCF + HF + Hg(61S0), which has been found to produce vibrationally-excited HF. Relative rate constants k(v) for vibrational levels v = 1–4 have been obtained. It appears that channelling of the potential energy into HF vibration, in the course of the elimination step, is more efficient in the first than in the second of these reactions. In the second reaction HF is eliminated with considerable rotational excitation.

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