Vibrational relaxation theories and measurements

Ormonde, Stephan

doi:10.1103/revmodphys.47.193

Cited by 113 publications

(14 citation statements)

References 338 publications

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“…Moreover, at temperatures above 200 "K, tlie use of total HF pressure in place of pi in Eq, (5) introduces a negligible error. 23 Therefore, in analysis of the experiments, the approximate expression W =h m X m +k n X xlv + Y, ÜnV^iTp"-1 , n>\ (6) where X m and X llv are the molo fractions of argon and HF, is applicable. Figures 1-3 present deactivation rate data for a low temperature (205 "K) and a higher temperature (~275 0 K).…”

Section: Resultsmentioning

confidence: 99%

Study of Molecular Lasers

Wolga¹,

Bauer²,

McFarlane³

et al. 1975

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Section: Resultsmentioning

confidence: 99%

Study of Molecular Lasers

Wolga¹,

Bauer²,

McFarlane³

et al. 1975

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“…This is a major task in itself and a great number both of theoretical and experimental papers have been dedicated to it over the past three decades. However, it is not of concern to us here and we refer the interested reader to the many excellent reviews that exist in the literature, such as Ormonde's paper on vibrational relaxation (Ormonde 1975).…”

Section: Introductionmentioning

confidence: 99%

Study of ICRF Wave Propagation and Absorption in INTOR Tokamak Plasma

Itoh

Fukuyama

1984

Jpn. J. Appl. Phys.

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The dynamics of vibrational energy relaxation by collisions in molecular beams and free jet expansions are examined. Within the stochastic approach afforded by the use of the master equation, the incomplete relaxation process may be modelled by assuming a time-dependent transition rate matrix. In particular, we prove that for non-degenerate levels and weak interactions the state distribution is Boltzmannian if the transition rate matrix is of the Landau-Teller type. The ramifications of this result on the analysis of recent studies of vibrational relaxation in seeded beams is briefly discussed.

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“…In particular, the H F molecule exhibits a marked ability to exchange rotational and vibrational energy even at low collision energies, where the ( v = 1) vibrational level is the one mainly involved in V,R/T process responsible for the above relaxation and appears to be associated with very large relaxation times over a wide interval of temperatures [7].…”

Section: Introductionmentioning

confidence: 99%

Vibrationally inelastic scattering and relaxation times in gaseous HF

Gianturco¹,

Lamanna

Battaglia³

1981

Int J of Quantum Chemistry

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AbstractsA numerical fit to computed ab initio points of the HF-HF potential energy surface is here employed in its simplest spherical form to solve the corresponding close-coupling equations that yield vibrationally inelastic collision cross sections for the V / T process in the gas phase. The existence of a deep potential well in the interaction is examined here for its effect on near-threshold cross section behavior and evidence is found, through the present calculations, for the relative importance of several (orbiting) shape resonances that contribute to the Ql,o cross sections at low collision energies (50.4 eV). The bearing of such lengthened interaction times on the corresponding low temperature relaxation times is shown in the ensuing calculation of p~ in the T range between 300 and 4000 K. In spite of the simplicity of the present model, quite good agreement is in fact found with experiments in the low-T region, while the lack of V , R / T coupling explains the departure of the computed p~, above 1000 K, from the experimental findings.Une adaptation numerique aux points d'une surface de potentiel HF-HF calcults ab initio est utilisie dans sa forme spherique la plus simple pour resoudre les equations de couplage fort correspondantes, qui fournissent des sections efficaces intlastiques du point de vue des vibrations pour le processus V / T dans la phase gazeuse. L'existance d'un puits de potentiel profond dans I'interaction est examinee du point de vue de son effet pour le comportement de la section efficace prks du seuil. Nos calculs dtmonstrent I'importance relative de plusieurs resonances de forme qui contribuent aux sections efficaces Ql,a ii des energies de collision basses (50.4eV). L'influence de ces temps d'interaction prolongis sur les temps de relaxation correspondants pour les basses temperatures est demontrte dans un calcul de pr pour T entre 300 et 400 K. Malgrt la simplicit6 du modde on trouve un accord assez bon avec les donntes experimentales pour les basses temperatures. D'autre part I'absence de couplage V , R / T explique la difference entre les valeurs de PT calcultes au-dessus de 1000 K et les valeurs exptkimentales.Eine numerische Anpassung zu ab-initio-berechneten Punkten auf einer HF-HF-Potentialenergieobedache wird in ihrer einfachsten spharischen Form benutzt, urn die entsprechenden Gleichungen fur starke Kopplung zu losen, die inelastische Schwingungsquerschnitte fur das V/ T-Prozess in der Gasphase liefern. Die Existenz eines tiefen Potentialtopfes in der Wechselwirkung wird mit Riicksicht auf seinen Effekt auf das Verhalten des Querschnitts in der Nahe der Schwelle untersucht. Unsere Berechnungen zeigen die relative Bedeutung von mehreren "Shape"-Resonanzen, die zu den Ql

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Vibrational relaxation theories and measurements

Cited by 113 publications

References 338 publications

Study of Molecular Lasers

Study of Molecular Lasers

Study of ICRF Wave Propagation and Absorption in INTOR Tokamak Plasma

Vibrationally inelastic scattering and relaxation times in gaseous HF

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