Two-photon excitation of atomic oxygen in a flame

Aldén, Marcus; Edner, Hans; Grafstrom, P; Svanberg, Sune

doi:10.1016/0030-4018(82)90025-6

Cited by 129 publications

(39 citation statements)

References 6 publications

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“…5 In a short period of time two-photon excitation laserinduced fluorescence detection of ground-state atoms was also reported for nitrogen, 6 oxygen, [6][7][8] chlorine, 9 sulfur, 10 carbon, 11 and fluorine. 12,13 After this pioneering work in which the measurement principle for these species was demonstrated, the two-photon LIF technique has been successfully applied to study a variety of reactive environments.…”

Section: Introductionmentioning

confidence: 91%

Quantitative two-photon laser-induced fluorescence measurements of atomic hydrogen densities, temperatures, and velocities in an expanding thermal plasma

Boogaarts

Mazouffre

Brinkman

et al. 2002

Review of Scientific Instruments

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We report on quantitative, spatially resolved density, temperature, and velocity measurements on ground-state atomic hydrogen in an expanding thermal Ar-H plasma using two-photon excitation laser-induced fluorescence ͑LIF͒. The method's diagnostic value for application in this plasma is assessed by identifying and evaluating the possibly disturbing factors on the interpretation of the LIF signal in terms of density, temperature, and velocity. In order to obtain quantitative density numbers, the LIF setup is calibrated for H measurements using two different methods. A commonly applied calibration method, in which the LIF signal from a, by titration, known amount of H generated by a flow-tube reactor is used as a reference, is compared to a rather new calibration method, in which the H density in the plasma jet is derived from a measurement of the two-photon LIF signal generated from krypton at a well-known pressure, using a known Kr to H detection sensitivity ratio. The two methods yield nearly the same result, which validates the new H density calibration. Gauging the new ''rare gas method'' by the ''flow-tube reactor method,'' we find a krypton to hydrogen two-photon excitation cross section ratio Kr ͑2͒ / H (2) of 0.56, close to the reported value of 0.62. Since the H density calibration via two-photon LIF of krypton is experimentally far more easy than the one using a flow-tube reactor, it is foreseen that the ''rare gas method'' will become the method of choice in two-photon LIF experiments. The current two-photon LIF detection limit for H in the Ar-H plasma jet is 10 15 m Ϫ3 . The accuracy of the density measurements depends on the accuracy of the calibration, which is currently limited to 33%. The reproducibility depends on the signal-to-noise ͑S/N͒ ratio in the LIF measurements and is orders of magnitude better. The accuracy in the temperature determination also depends on the S/N ratio of the LIF signal and on the ratio between the Doppler-width of the transition and the linewidth of the excitation laser. Due to the small H mass, the current linewidth of the UV laser radiation is never the accuracy limiting factor in the H temperature determination, even not at room temperature. Quantitative velocity numbers are obtained by measuring the Doppler shift in the H two-photon excitation spectrum. Both the radial and axial velocity components are obtained by applying a perpendicular and an antiparallel excitation configuration, respectively. The required laser frequency calibration is accomplished by simultaneously recording the I 2 absorption spectrum with the fundamental frequency component of the laser system. This method, which is well-established in spectroscopic applications, enables us to achieve a relative accuracy in the transition frequency measurement below 10 Ϫ6 , corresponding to an accuracy in the velocity of approximately 200 m/s. This accuracy is nearly laser linewidth limited.

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Section: Introductionmentioning

confidence: 91%

Quantitative two-photon laser-induced fluorescence measurements of atomic hydrogen densities, temperatures, and velocities in an expanding thermal plasma

Boogaarts

Mazouffre

Brinkman

et al. 2002

Review of Scientific Instruments

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“…2 1 As has been demonstrated in this Letter, NO and NO 2 can be detected simultaneously by using only one laser pulse. This can be compared with our previous two-species LIF experiments, 5 in which two completely different laser systems were used. In these experiments the two species (C 2 and OH) were detected separately by using a special mirror arrangement creating two images and different optical filters.…”

mentioning

confidence: 99%

“…4 The imaging technique was also extended to two-species (C2, OH) detection by using two separate laser systems. 5 The second achievement was the introduction of multiphoton absorption processes, which made it possible to detect atoms and molecules, e.g., 0, H, C, and CO, that absorb in the VUV spectral region and therefore are impossible to detect by a one-photon transition because of large molecular absorption at these wavelengths. Much of the groundwork concerned with the detection of light atoms (0, N) was carried out by Bischel et al 6 under well-controlled conditions.…”

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confidence: 99%

Simultaneous spatially resolved NO and NO_2 measurements using one- and two-photon laser-induced fluorescence

1985

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“…1,[3][4][5][6] Many investigations have been done to measure important parameters that affect the different processes that the CO molecule will undergo in two-photon LIF, e.g., absorption and excitation cross section, 7 spectral broadening, 8 collisional quenching, 9,10 photoionization, 11 and fluorescence lift times. 12,13 For two-photon CO LIF in combustion systems, the most common excitation wavelength is 230.1 nm, matching the…”

Section: Introductionmentioning

confidence: 99%

Comparison of Three Schemes of Two-Photon Laser-Induced Fluorescence for CO Detection in Flames

et al. 2013

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Two-photon excitation laser-induced fluorescence of carbon monoxide suffers from interference from mainly C 2 and strong pressure quenching. This paper presents an investigation of three excitation/detection schemes for two-photon excitation laser-induced fluorescence on carbon monoxide. The schemes are evaluated for pressure and quenching partner dependencies and C 2 interference. Three different emission bands lie in the Hopefield-Birge system: The Å ngström B 1 R 3 R!a 3 P, also with excitation of B 1 R þ X 1 P around 230 nm. The measurements are performed in laminar premixed flames with various equivalence ratios as well as in a high-pressure cell, where pressure and species concentrations are varied in order to investigate the fluorescence quenching dependence.

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Two-photon excitation of atomic oxygen in a flame

Cited by 129 publications

References 6 publications

Quantitative two-photon laser-induced fluorescence measurements of atomic hydrogen densities, temperatures, and velocities in an expanding thermal plasma

Quantitative two-photon laser-induced fluorescence measurements of atomic hydrogen densities, temperatures, and velocities in an expanding thermal plasma

Simultaneous spatially resolved NO and NO_2 measurements using one- and two-photon laser-induced fluorescence

Comparison of Three Schemes of Two-Photon Laser-Induced Fluorescence for CO Detection in Flames

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