Is the flow tube reactor with NO2 titration a reliable absolute source for atomic hydrogen?

Niemi, Kari; Mosbach, Thomas; Döbele, H. F.

doi:10.1016/s0009-2614(02)01742-6

Cited by 11 publications

(13 citation statements)

References 6 publications

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“…Titration with a flow-tube reactor is commonly applied as a reference source for calibration [20]. Recently it was shown that a titration scheme allows a spatially not resolved measurement of the atomic nitrogen concentration in the effluent of a similar discharge [21].…”

Section: Two-photon Absorption Laser-induced Fluorescencementioning

confidence: 99%

Optical Diagnostics of Micro Discharge Jets

Gathen

Buck

Gans

et al. 2007

Contrib. Plasma Phys.

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Micro plasmas operated at ambient pressure with dimensions of the confining geometry in the order of a few ten micrometers to a millimeter are actually in the focus of interest due to the broad regime of applicability they offer and due to a similarly broad range of open physical questions. Here we present optical measurements within the discharge core and the effluent region of an especially developed micro discharge jet. To get an understanding of the complex system of this discharge it is important to analyse transport phenomena of energy and particles within both parts of the discharge by various highly sophisticated diagnostics. As a consequence of the limited access and the dimensions of the micro discharge most of these diagnostics are optical. Here we present diagnostics applied to determine spatially resolved absolute atomic oxygen densities as the most reactive constituent of the effluent, density maps of ozone as final reaction product of the gas chemical chain induced by the discharge and phase resolved optical emission spectroscopy yielding insight into the excitation dynamics of the discharge.

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Section: Two-photon Absorption Laser-induced Fluorescencementioning

confidence: 99%

Optical Diagnostics of Micro Discharge Jets

Gathen

Buck

Gans

et al. 2007

Contrib. Plasma Phys.

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“…The method of TALIF calibration with noble gases for the determination of absolute atomic ground state densities has been introduced by Goehlich et al [19]. It represents a technically simple alternative to the use of atomic reference sources like the flow-tube reactor with titration [20]. The method is based on comparative TALIF measurements using a noble gas as a reference with a two-photon resonance spectrally close to that of the atomic species to be quantified.…”

Section: Absolutely Calibrated Talif Measurements Of Atomic Oxygenmentioning

confidence: 99%

Diagnostics on an atmospheric pressure plasma jet

Niemi

Reuter

Schaper

et al. 2007

J. Phys.: Conf. Ser.

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The atmospheric pressure plasma jet (APPJ) is a homogeneous non-equilibrium discharge at ambient pressure. It operates with a noble base gas and a percentage-volume admixture of a molecular gas. Applications of the discharge are mainly based on reactive species in the effluent. The effluent region of a discharge operated in helium with an oxygen admixture has been investigated. The optical emission from atomic oxygen decreases with distance from the discharge but can still be observed several centimetres in the effluent. Ground state atomic oxygen, measured using absolutely calibrated two-photon laser induced fluorescence spectroscopy, shows a similar behaviour. Detailed understanding of energy transport mechanisms requires investigations of the discharge volume and the effluent region. An atmospheric pressure plasma jet has been designed providing excellent diagnostics access and a simple geometry ideally suited for modelling and simulation. Laser spectroscopy and optical emission spectroscopy can be applied in the discharge volume and the effluent region.

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“…They are, therefore, better suited to accurate quantitative investigations [9]. The major disadvantage compared with OES are relatively high experimental requirements and comparatively long measurement times, making it less favourable for monitoring processing plasmas.…”

Section: Introductionmentioning

confidence: 99%

Determination of the degree of dissociation in an inductively coupled hydrogen plasma using optical emission spectroscopy and laser diagnostics

Abdel-Rahman

Gathen

Gans

et al. 2006

Plasma Sources Sci. Technol.

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The knowledge of absolute concentrations of radicals in molecular discharges, such as the density of atomic hydrogen in H 2 plasmas, is crucial for understanding processes at the surface and is, therefore, of great interest in a variety of plasma applications. Reliable spectroscopic methods are indispensable for the determination of the degree of dissociation in processing plasmas. In this paper, we describe a novel optical emission spectroscopy method called two-gas actinometry (TGA). It is based on using a second actinometer gas to take into account dissociative excitation, which is of particular importance at comparatively low degrees of dissociation. TGA is employed for measuring the characteristic dependence of the degree of dissociation, in a wide range of plasma parameters, in an inductively coupled radio-frequency hydrogen plasma. Absolute densities with high accuracy are obtained using two-photon absorption laser-induced fluorescence spectroscopy.

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Is the flow tube reactor with NO2 titration a reliable absolute source for atomic hydrogen?

Cited by 11 publications

References 6 publications

Optical Diagnostics of Micro Discharge Jets

Optical Diagnostics of Micro Discharge Jets

Diagnostics on an atmospheric pressure plasma jet

Determination of the degree of dissociation in an inductively coupled hydrogen plasma using optical emission spectroscopy and laser diagnostics

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