摘要:

AbstractExperimental evidence of parametric excitation, by an intense external H.F. field, of an electron surface mode and an ion wave is presented. The pumping electromagnetic energy density is equal to or slightly larger than the thermal energy density of the electrons.The value offpc/f0(electron plasma frequency/external field frequency) is that for an electron surface wave. Depending on the pressure and field intensity, this decay instability can lead to three types of low frequency oscillations, with frequencies close to the ion plasma frequency. Two of these are described by Aliev and Silin's intense field theory: one is the volume ion plasma oscillation and the other a surface ion plasma oscillation. The third corresponds to no known ion eigenmode.Several other features of the theory by Aliev and co‐workers are also confirmed experimentally, such as the harmonic excitation of the instability (nf0≈fpe/√2, wherenis an integer), the instability amplitude as a function offpe/f0(above threshold conditions), the value of the mismatch parameter as a function of field strength and ion mass, and the existence of a fine structure corresponding to the symmetric and antisymmetric electron surface oscillations.Even at high pump field strengths, the decay products are nearly monochromatic i.e. the plasma does not become turb

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150302

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractParametric resonance phenomena are investigated in a plasma layer with thicknessdand thin inhomogeneous boundary regions. The modulated UHF electric field is parallel to the plasma layer. We consider both strong and low modulation of the field amplitude and suppose, that the carrier frequency ω0of the pump wave is much larger than the Langmuir frequency ωLe. We find the region for the modulation frequency ω, in which the parametric growing of the asymmetric and symmetric surface waves occurs. The maximum growth rates of these waves, the direction of their propagation and the threshold value of the modulation depth α of the UHF pump field are calculat

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150303

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractFür die Fälle der direkten und der Stufenionisation bei konstanter Elektronentemperatur werden die Radialverteilungen der Elektronenkonzentration und der Neutralgastemperatur in Abhängigkeit von der in der Säule erzeugten Wärme numerisch berechnet. Bei der Darstellung der Kenndaten und Mittelwerte der Radialverteilungen wird der Aspekt der praktischen Anwendbarkeit besonders berücksic

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150304

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

ISSN:0005-8025    

DOI:10.1002/ctpp.19750150301

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY