Discussion of two-photon laser-excited fluorescence as a method for quantitative detection of oxygen atoms in flames

Meier, Ulrich; Bittner, Jürgen; Kohse‐Höinghaus, Katharina; Just, Th.

doi:10.1016/s0082-0784(89)80203-6

Cited by 14 publications

(28 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Considering the uncertainties in the measurement of pulse energies below 100 ~tJ and in the determination of the focal spot size, as well as the variation in laser energy associated with the rapid decay of the dye solution, the overall range of power density in the experiments was 2 × 107-2 × 108 W cm -2, with a maximum variation of less than a factor of 2 within this range for an individual experiment. Similar power densities of about 5 x 107Wcm -2 were found suitable for avoiding photodissociative O atom production when measuring O atom concentrations in low-pressure H2/O2/Ar flames [20].…”

Section: Fig 1 Experimental Arrangementmentioning

confidence: 67%

“…The main features of the experimental set-up were similar to the apparatus used before for the quantitative detection of H [19] and O atoms [20] in flames. A schematic of the experimental arrangement is given in Fig.…”

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

“…Various multi-photon excitation techniques have been used to detect hydrogen and oxygen atoms in flames [13][14][15][16][17][18]. In our group, we have recently developed a calibration method which allows spatially resolved measurements of H and O atom concentrations in low-pressure flames [19,20]. This method relies on a discharge flow reactor as a calibration standard: The two-photon laser-excited fluorescence signal arising from a known atom concentration produced in the flow reactor under identical excitation and detection conditions is related to the fluorescence signal produced by the unknown atom concentration at a particular location in the flame.…”

mentioning

confidence: 99%

“…For this purpose, it seemed desirable to start from reasonably wellknown flame conditions as provided, for example, by the low-pressure H2/O2 flames studied in our group before [19][20][21][22][23]. Small amounts of HCN, (CN)2, or NH3 were added as N atom precursors to H2/O2 flames diluted with N2.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Nitrogen atom detection in low-pressure flames by two-photon laser-excited fluorescence

Bittner¹,

Lawitzki²,

Meier³

et al. 1991

Appl. Phys. B

Self Cite

View full text Add to dashboard Cite

Abstract. Nitrogen atoms have been detected in stoichiometric flat premixed H2/O2/N2 flames at 33 and 96 mbar doped with small amounts of NH3, HCN, and (CN)2 using two-photon laser excitation at 211 nm and fluorescence detection around 870nm. The shape of the fluorescence intensity profiles versus height above the burner surface is markedly different for the different additives. Using measured quenching rate coefficients and calibrating with the aid of known N-atom concentrations in a discharge flow reactor, peak N-atom concentrations in these flames are estimated to be on the order of 1012-5 × 1013 cm -3 ; the detection limit is about 1 × 1011 cm -3. PACS: 82.40Py, 33.50Dq In the combustion of nitrogen-containing fuels, a variety of conditions have been identified under which atomic nitrogen is of importance. For example, N atoms can influence the product distribution in the conversion of fuelbound nitrogen to N2 or NOx. Depending on the particular nitrogen source and the temperature and equivalence ratio of the combustion process, the reactions of N atoms with e.g. OH, NO, or CH3 can lead to the formation of NO, N2, or HCN. A detailed treatment of the gas-phase nitrogen chemistry in combustion can be found in the recent review by Miller and Bowman [1].Nitrogen atom concentrations have been measured by ESR [2] and by atomic resonance absorption (ARAS) [3]. ESR spectroscopy has been used to detect N atoms in discharge flow reactors [2]. The ARAS technique requires vacuum UV radiation for the detection of N atoms; although it has proven most successful in shock tube experiments [3], flames usually are not transparent for these short wavelengths. Molecular beam sampling techniques coupled with mass spectrometry [4] were used in an investigation of the structure of a 45mbar NH3/O2/Ar flame. In this experiment, N concentrations were found to be below the detection limit (10 .5 ) of the apparatus throughout the flame. Their role in the kinetic mechanism was thus judged to be marginal [4]. The recent kinetic model of [1], however, predicts for this flame a mole fraction of N atoms which is about a factor of 30 higher than the upper limit stated in [4]. Upon addition of small amounts of HCN as N-containing fuel to a 33 mbar H2/O2/Ar flame, Miller etal. [5] find that the NO mole fraction is very sensitive to nitrogen atom reactions. Their conclusions on the importance of N atoms in the processes of NO formation and of conversion of NO to N2 under these conditions are in agreement with earlier work of Haynes [6] and Morley [7]. Although N atoms were not detected in their experiment, Miller et al. [5] predict N atom mole fractions of 5 x 10 .5 to 10 -4 in their flames. In the context of these different flame studies, the bxperimental det'ermination of N atom concentrations for specific combustion situations is expected to provide information which might be used to examine current chemical-kinetic models of the nitrogen chemistry in flames.Two-photon laser-induced fluorescence is a non-perturbing optical diagnostic tech...

show abstract

Section: Fig 1 Experimental Arrangementmentioning

confidence: 67%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Nitrogen atom detection in low-pressure flames by two-photon laser-excited fluorescence

Bittner¹,

Lawitzki²,

Meier³

et al. 1991

Appl. Phys. B

Self Cite

View full text Add to dashboard Cite

show abstract

Antagonistic Functionalized Nucleation and Oxidative Degradation in Combustive Formation of Pyrene‐Based Clusters Mediated by Triplet O and O₂: Theoretical Study

Maranzana

Tonachini

2015

ChemPhysChem

View full text Add to dashboard Cite

Abstract.Polycyclic aromatic hydrocarbons (PAHs) and carbonaceous nanoparticles can be oxidized right from their inception and all through their growth. Oxidation can promote their degradation too. This modelistic density functional theory (DFT) study explores in a descriptive manner if oxidation can mediate the earliest nucleation stages ("functionalized nucleation"), though contrasted by mass declension triggered by oxidation itself. An initial O (

show abstract

Saturated 2D-LIF of OH and 2D determination of effective collisional lifetimes in atmospheric pressure flames

1991

View full text Add to dashboard Cite

Discussion of two-photon laser-excited fluorescence as a method for quantitative detection of oxygen atoms in flames

Cited by 14 publications

References 14 publications

Nitrogen atom detection in low-pressure flames by two-photon laser-excited fluorescence

Nitrogen atom detection in low-pressure flames by two-photon laser-excited fluorescence

Antagonistic Functionalized Nucleation and Oxidative Degradation in Combustive Formation of Pyrene‐Based Clusters Mediated by Triplet O and O₂: Theoretical Study

Saturated 2D-LIF of OH and 2D determination of effective collisional lifetimes in atmospheric pressure flames

Contact Info

Product

Resources

About

Discussion of two-photon laser-excited fluorescence as a method for quantitative detection of oxygen atoms in flames

Cited by 14 publications

References 14 publications

Nitrogen atom detection in low-pressure flames by two-photon laser-excited fluorescence

Nitrogen atom detection in low-pressure flames by two-photon laser-excited fluorescence

Antagonistic Functionalized Nucleation and Oxidative Degradation in Combustive Formation of Pyrene‐Based Clusters Mediated by Triplet O and O2: Theoretical Study

Saturated 2D-LIF of OH and 2D determination of effective collisional lifetimes in atmospheric pressure flames

Contact Info

Product

Resources

About

Antagonistic Functionalized Nucleation and Oxidative Degradation in Combustive Formation of Pyrene‐Based Clusters Mediated by Triplet O and O₂: Theoretical Study