摘要:

AbstractDifferent methods have been proposed in the past for calculating the atomic ion‐electron recombination coefficient of plasmas, for example collisional‐radiative models of D'ANGELO (1961) and of BATES et al. (1962); the “bottleneck” models of HINNOV and HIRSCHBERG (1962) and BYRON et al. (1962) modified by CHEN (1969) and WANLESS (1971); the variational theory of MAKIN and KECK (1963), modified by CURRY (1970); the J. J. THOMSON method modified by D'ANGELO (1965). Using the appropriate atomic parameters the recombination coefficients were calculated for a wide range of electron temperatures and electron densities for optically thin and optically thick hydrogen and helium plasmas. The characteristic discrepancies between the different theories are discussed. To be mentioned is the relative good agreement of the “bottleneck” models and the complete collisional‐radiative theory for optically thin and thick hydrogen plasmas at nearly all temperatures, but the agreement is less good for helium plasmas especially in the optically thick case at elevated temperatures. It is the first time that such a comparative study based on a consistent set of atomic parameters has be

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150602

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThis paper reports on measurements of probe noise and double probe characteristics in argon‐low‐pressure low‐current discharges under the influence of a local transversal magnetic field. Above a critical value of magnetic field intensityBcthere are no moving striations but partially correlated fluctuations. The space distribution of probe noise (ion saturation current and floating potential) and the measured values of electron temperature and density are discussed. AtBca characteristic value of electron temperatureTe,c≈ 1,4 eV independent of filling pressure has been found. A first opinion on the character of the fluctuations i

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150603

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractMeasurements of electrical conductivity with small experimental error limits forXe(T= 10000 to 14500 K) and Ar (T= 15000 ‐ 19000 K) are compared with a conductivity formula for fully ionized plasma derived from the BOLTZMANN‐equation using the treatment of SCHIRMER. The theoretical curves fit the experiments if the cut off parameter is chosen asa0= 2,5Din the case of Xe anda0= 4Din the case of Ar, whereDis the DEBYE shielding parameter. These different values fora0indicate an influence of the gas species even in the case of full ionization. It has been shown that both the BOLTZMANN collision term and the FOKKER‐PLANCK collision term yield the same results and that the discrepancies between the different published treatments are due to unjustified physical or mathematical simplifica

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150604

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractOn the example of the Ne glow discharge with a benzol admixture the possibility of applicating the probe diagnostic in polymerizing plasmas is investigated. Heating the probe at 900°C stetady values for the floating potential, the probe characteristic and its second derivation are obtained. The variation with time of these quantities without heating the probe yields informations about the rate of polymerization. The effect of a benzol admixture from 1% to 20% on the energy distribution function of electrons and the plasma parameters in the tube axis is pointed out. From the second derivation of the characteristic at emissive probe conditions it is possible to deduce in addition to the space potential the influence of the benzol admixture on the ionization mechanism

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150605

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe synthesis of ozone on the surfaceScooled with liquid nitrogen O + O2·S→O3·S[1] was used to measure the concentration of atoms in a flow tube downstream of a d.c. discharge. The flow tube was constructed in the form of a U‐tube. The ozone was deposited as a blue liquid film in the neighbourhood of the surface of the liquid nitrogen on the walls of the part of the U‐tube, which was connected with the discharge tube. The oxygen atom decay in the U‐tube was observed by measuring the production of ozone as the distance between the discharge tube (diameter: 5,2 cm) and the surface of the liquid nitrogen was varied. The decay is first order in atom concentration for the pressuresp>1 torr. But for the pressures belowp= 1 torr near by the discharge tube we observed deviations from the law of decay In [O]0/[O] = k·t for the currents of abouti= 100 mA.This effect was attributed to the process\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm O + O + M} \to {\rm O}_{\rm 2} {\rm + M,}} & {{\rm M} = {\rm O}_2 (^3 \sum _g ^ -),{\rm O}_2 (^1 \Delta _g),{\rm O}_2 (^1 \sum _g ^ +).} \\ \end{array} $$\end{document}From the extrapolation of an ozone production curve atom concentrations in the discharge have been obtained. The transition from the „H”︁ form to the „T”︁ form (striated, low average electric field) of the discharge [2] caused the dissociation to decrease rapidly. The highest dissociation (10%) was obtained in the „H”︁ form at high currents (i= 120 mA) and low pressures (p= 0,60 torr).The yield of atomic oxygen per kilowatt hour of energy was measured as functions of pressure and gas flow r

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150606

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe functions of thermal conductivity α(T) and electrical conductivity σ(T) for water vapour, within the temperature intervals 7700–8000 K and 2000–3500 K, were calculated. These calculations were performed by using the UHLENBUSCH'S method and the empirical one. Calculations were based on experimentally determined electric field strength as a function of the arc current and radial temperature distribution in the central zone and in the surrounding of the arc burning in water vapour atmos

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150607

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe dispersion characteristics of a plasma in a pump field

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150608

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe formula for the ion density is corrected. Furthermore, for different accommodation coefficients at the wall numerical values of the neutral atom velocities in argon ion lasers are estimated. The neutral gas heating by electron collisions is relatively small in argon ion lasers.

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150609

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150601

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY