scholarly journals Emission and Relaxation of Electronically Excited O2 Doped in a Low Temperature N2 Crystal

1995 ◽  
Vol 15 (2-4) ◽  
pp. 83-92 ◽  
Author(s):  
Hideo Kajihara ◽  
Tomoyuki Okamura ◽  
Fumio Okada ◽  
Seiichiro Koda
Keyword(s):  
Low Temperature ◽  
Vibrational Relaxation ◽  
Laser Excitation ◽  
Wave Length ◽  
Pulsed Laser ◽  
Intersystem Crossing ◽  
Additional Mechanism ◽  
Excitation Wave ◽  
Vibrational Levels ◽  
Electronically Excited

Oxygen molecules doped in a low temperature N2 crystal were irradiated at 240-260 nm. Two emission band systems were observed, one from the v′ = 0 level of A′ 3Δu state to X3Σg-. state and the other, from the v′ = 0 level of c1Σu-. state to at a1Δg state, independent on the excitation wave length. The latter emission grew together with the decay of the former emission at around the same rate after the pulsed laser excitation, which implies that the vibrational levels of c state lying below the v′ = 0 level of Ω = 3 of A′ state are populated from the v′ = level of A′ state, though some additional mechanism for populating the c state may exist. The rate was found to become larger with the increase of the crystal temperature. It was also found that the excitation spectrum obtained by monitoring the A′–X emission was the same as that obtained by the c–a emission. The progress of vibrational relaxation, coupling with the intersystem crossing between the Herzberg states, will be discussed.

scholarly journals Reactive quenching of electronically excited NO<sub>2</sub><sup>∗</sup> and NO<sub>3</sub><sup>∗</sup> by H<sub>2</sub>O as potential sources of atmospheric HO<sub><i>x</i></sub> radicals

2018 ◽  
Vol 18 (19) ◽  
pp. 14005-14015 ◽  
Author(s):  
Terry J. Dillon ◽  
John N. Crowley
Keyword(s):  
Gas Phase ◽  
Laser Excitation ◽  
Pulsed Laser ◽  
Work Rate ◽  
Rate Coefficients ◽  
Phase Reaction ◽  
Gas Phase Reaction ◽  
Upper Limit ◽  
Upper Limits ◽  
Electronically Excited

Abstract. Pulsed laser excitation of NO2 (532–647 nm) or NO3 (623–662 nm) in the presence of H2O was used to initiate the gas-phase reaction NO2∗+H2O → products (Reaction R5) and NO3∗+H2O → products (Reaction R12). No evidence for OH production in Reactions (R5) or (R12) was observed and upper limits for OH production of k5b/k5<1×10-5 and k12b/k12<0.03 were assigned. The upper limit for k5b∕k5 renders this reaction insignificant as a source of OH in the atmosphere and extends the studies (Crowley and Carl, 1997; Carr et al., 2009; Amedro et al., 2011) which demonstrate that the previously reported large OH yield by Li et al. (2008) was erroneous. The upper limit obtained for k12b∕k12 indicates that non-reactive energy transfer is the dominant mechanism for Reaction (R12), though generation of small but significant amounts of atmospheric HOx and HONO cannot be ruled out. In the course of this work, rate coefficients for overall removal of NO3∗ by N2 (Reaction R10) and by H2O (Reaction R12) were determined: k10=(2.1±0.1)×10-11 cm3 molecule−1 s−1 and k12=(1.6±0.3)×10-10 cm3 molecule−1 s−1. Our value of k12 is more than a factor of 4 smaller than the single previously reported value.

scholarly journals Reactive quenching of electronically excited NO<sub>2</sub><sup>*</sup> and NO<sub>3</sub><sup>*</sup> by H<sub>2</sub>O as potential sources of atmospheric HO<sub><i>x</i></sub> radical

2018 ◽  
Author(s):  
Terry J. Dillon ◽  
John N. Crowley
Keyword(s):  
Gas Phase ◽  
Laser Excitation ◽  
Pulsed Laser ◽  
Gas Phase Reactions ◽  
Upper Limits ◽  
Potential Sources ◽  
Electronically Excited

Abstract. Pulsed laser excitation of NO2 (532–647 nm) or NO3 (623–662 nm) in the presence of H2O was used to initiate the gas-phase reactions NO2* + H2O → products (R5) and NO3* + H2O → products (R12). No evidence for OH production in (R5) or (R12) was observed and upper-limits for OH production of k5b/k5 

Altitude dependence of the vibrational distribution of in the nightglow and the possible effects of vibrational excitation in the formation of O(1S)

1984 ◽  
Vol 62 (8) ◽  
pp. 780-788 ◽  
Author(s):  
I. C. McDade ◽  
E. J. Llewellyn ◽  
R. G. H. Greer ◽  
G. Witt
Keyword(s):  
Vibrational Relaxation ◽  
Vibrational Excitation ◽  
Relaxation Model ◽  
Terrestrial Atmosphere ◽  
Transfer Step ◽  
Vibrational Distribution ◽  
Altitude Dependence ◽  
Vibrational Levels ◽  
The Individual

A simple vibrational relaxation model that reproduces the observed vibrational distribution of the [Formula: see text] Herzberg II bands in the terrestrial nightglow is used to derive the altitude profiles of the fractional populations in the individual vibrational levels. Through consideration of these profiles it is shown that if [Formula: see text] is the Barth precursor of O(1S) in the nightglow then, at least in the terrestrial atmosphere, the higher vibrational levels appear to be more effective in the Barth transfer step than the lower vibrational levels.

INTERSYSTEM CROSSING OF THE ELECTRONICALLY EXCITED DIDEUTEROETHYLENE MOLECULES FORMED IN BENZENE PHOTOSENSITIZATION

1966 ◽  
Vol 44 (18) ◽  
pp. 2173-2180 ◽  
Author(s):  
Terumi Terao ◽  
Shun-Ichi Hirokami ◽  
Shin Sato ◽  
R. J. Cvetanović
Keyword(s):  
Excited State ◽  
Experimental Evidence ◽  
Rate Constants ◽  
Intersystem Crossing ◽  
Molecular Decomposition ◽  
Electronically Excited

Experimental evidence is presented for a rapidly occurring intersystem crossing of the electronically excited dideuteroethylene molecules initially formed in the benzene-photosensitized reaction at 2 537 Å and 25 °C to another excited state which is responsible for the internal H-atom scrambling. The mechanism is entirely analogous to that previously postulated for the photoexcited states sensitized by Hg(3P1) atoms but the rate constants for intersystem crossing and molecular decomposition are drastically decreased as a result of the smaller amount of energy available for the excitation.

Broadband Optical Limiting and CCD Sensor Protection From Nanosecond-Pulsed Laser Threat With Reverse Saturable Absorbers

1997 ◽  
Vol 479 ◽  
Author(s):  
V. Dentan ◽  
P. Feneyrou ◽  
F. Soyer ◽  
M. Vergnolle ◽  
P. Le Barny ◽  
...  
Keyword(s):  
Excited States ◽  
Nonlinear Optical ◽  
Laser Excitation ◽  
Pulsed Laser ◽  
Saturable Absorbers ◽  
Nanosecond Pulsed Laser ◽  
Optical Limiter ◽  
Linear And Nonlinear ◽  
Ccd Arrays ◽  
Pulsed Laser Irradiation

AbstractWe study in detail the linear and nonlinear optical properties of a heavy metal substituted naphthalocyanine reverse saturable absorber (RSA). The excited states involved in the RSA process under nanosecond pulsed laser excitation in the visible are fully characterized. We then demonstrate that this material can be used as an efficient optical limiter for protecting silicium CCD arrays from destruction due to nanosecond-pulsed laser irradiation in the visible.

Effect of oxygen pressure performance of PZO thin films deposited by pulsed laser deposition at low temperature

2017 ◽  
Vol 727 ◽  
pp. 1273-1279 ◽  
Author(s):  
Shihui Yu ◽  
Binhui Zhu ◽  
Haoran Zheng ◽  
Lingxia Li ◽  
Siliang Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Pulsed Laser Deposition ◽  
Oxygen Pressure ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Effect Of Oxygen
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