摘要:

AbstractResults of spectral and photometric measurements are presented for pulsed operated high‐pressure‐sodium lamps. Choosing for the colour temperature a value of 3000 K, the output spectrum was optimized with respect to colour rendition and lamp efficacy taking the pulse parameters, the sodium mole fraction, and the cold spot temperature as quantities to be varied. For the nominal rating of 70 W a maximum lamp efficacy of 70 lm/W and a colour rendering index of 40 can be obtained. Further improvements of the colour rendition require an enhanced sodium vapour pressure which can be achieved by operating the lamp at rised cold spot temperat

ISSN:0863-1042    

DOI:10.1002/ctpp.2150300603

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractIn this paper an example is given for measurement and calculation of the energy influx towards a substrate during plasma processing in a supersonic reactor. From the results the energy transfer coefficients are obtained for several pressures. Also the evolution of the profile of the temperature is presented.

ISSN:0863-1042    

DOI:10.1002/ctpp.2150300604

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractA low‐temperature oxygen plasma is studied using the thermocouple, probe and spectral method in the range of 2–8 Torr pressure, 30–100 mA discharge currents, 0, 5, 10 m/s pumping velocity. The gas temperature, concentrations of electrons and oxygen atoms in the3p5Pstate, and the longitudinal electric field are measured. Radial distributions of gas temperature and electron concentration are obtained. Ranges of pressures and currents are found in which considerable increases in electric field, discharge voltage, temperatures of gas and electrons are observed at pumping switched on. An estimate of the rate constant of the steplike ionization through the O2(a1Δg) state is given. The concentration of atomic oxygen in the ground state and excitation constant of the triplet O(3p5P) by electron impact are obtained from the solution of the balance equations and our experimenta

ISSN:0863-1042    

DOI:10.1002/ctpp.2150300605

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractUnimolecular dissociation of metastable excited states of (O2)n−* into (O2) n‐1−cluster anions has been detected and studied quantitatively fornin the range of 13 to 22. The apparent metastable (decay rates determined increase with cluster size in from ∼ 5000 s−1(forn= 13) up to ∼ 8500

ISSN:0863-1042    

DOI:10.1002/ctpp.2150300606

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractThe dispersion of nonsymmetrical electromagnetic waves in waveguide, partially filled with plasma, is studied numerically and experimentally. An external d.c. coaxial magnetic field is applied to the waveguide. The dispersion equation of these waves is obtained, and it is solved numerically for the experimental conditions. Results are obtained, which show coupling of the waveguide HEl1‐modes with the family of the high‐frequency plasma HEln‐modes. The numerical dispersion curves are experimentally examined, and the influence of the magnetic field and the plasma density is st

ISSN:0863-1042    

DOI:10.1002/ctpp.2150300607

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractThe dispersion of electromagnetic waves in waveguides partially filled with semiconductor plasma is investigated for unmagnetized and for strongly magnetized plasma.The effects which may be useful for the plasma electronics are found: In such waveguides there exist a large number of slow waves with typical frequencies ω ≈ ωP/√ϵL. The filling at which the different modes at fixed phase velocity are maximum separated in wavelength is found. The thickness of the semiconductor layer at which this effect arises is about hundred micrometers and depends on the crystals' type. In addition to this, in strongly magnetized semiconductor plasma the maximum frequency separation of the typical plasma waves is found at fixed filling.Is it shown that in such systems there exist many surface waves which are of the slow wave type.In the case of strongly magnetized plasma coupling between nonsymmetrical EH‐ and HE‐ modes is show

ISSN:0863-1042    

DOI:10.1002/ctpp.2150300608

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractThe non‐relativistic dispersion relation for ordinary‐waves propagating in a hot plasma confined by magnetic mirrors is derived under small gyroradius approximation. The hot electron velocity distribution is modelled by a bi‐Maxwellian with a cutoff at the loss‐cone boundary. The dispersion relation is analyzed from propagation point of view. It is seen that the presence of loss cones in the electron velocity distribution reduces the high temperature effects in the ordinary‐wave propagation charac

ISSN:0863-1042    

DOI:10.1002/ctpp.2150300609

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractThe gravitational instability of a two component plasma is studied to include the simultaneous effects of collisions, gyroviscosity, finite conductivity, viscosity and porosity of the medium within the framework of two‐fluid theory. From linearized equations of the system, using normal mode analysis, the dispersion relations for parallel and perpendicular directions to the magnetic field are derived and discussed. For longitudinal wave propagation it is found that the value of critical JEANS' wave number increases with increasing density and decreasing temperature of the neutral component. For transverse wave propagation the value of critical JEANS' wave number depends on gyroviscosity, ALFVÉN number, ratio of sonic speeds and densities of the two component and porosity of the medium. It is observed that the effect of magnetic field and porosity is suppressed by finite condutivity of the plasma and similarly the effect of gyroviscosity is removed by viscosity from JEANS' expression of instability.For both the directions instability is produced when the velocity perturbations are considered parallel to wave vector. The damping effect is produced due to collisional frequency, permeability of the porous medium and viscosity. The density of the neutral component and porosity of the medium tends to destabilize the system while an increased value of FLR corrections leads the system towards stabilizati

ISSN:0863-1042    

DOI:10.1002/ctpp.2150300610

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractThe variation of density and flow speed of ions in a laser produced plasma as function of the intensity of the wave for different beam width parameter is studied. It is found that self‐focusing of the beam increases the density and decreases the velocity in the overdense region whereas it decreases the density and increases the velocity in the underdense regio

ISSN:0863-1042    

DOI:10.1002/ctpp.2150300611

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0863-1042    

DOI:10.1002/ctpp.2150300612

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY