WorldCat Identities

Arnush, Donald

Works: 5 works in 6 publications in 1 language and 6 library holdings
Publication Timeline
Most widely held works by Donald Arnush
High intensity laser propagation in the atmosphere( Book )

2 editions published in 1967 in English and held by 2 WorldCat member libraries worldwide

The phenomena which constitute ultimate limitations to the transmission of intense laser radiation through the atmosphere are investigated, namely, self-defocusing due to atmospheric heating and the stimulated Raman effect. The heating studies are concerned with processes contributing to residual absorption in atmospheric transmission windows. A quantum mechanical study of the far-wing pressure broadening of molecular vibrational lines is carried out. The spectral distance beyond which the Lorentz-type behavior fails is found as a function of temperature and range of the interaction potential. It is shown that far wing fall-off is exponential. An analysis is made of collision induced absorption with emphasis on the far-wing behavior. A calculation is performed specifically for absorption during collisions between rare gas atoms; a numerical computation phase remains. Laser beam depletion by stimulated Raman scattering is investigated using a rate equation description. The particular effects are the interaction of competing Raman backscattered light, and the effect of pressure dependence on the propagation of a beam vertically through the atmosphere. The maximum intensity which can be transmitted through the atmosphere without frequency change due to Raman scattering is calculated. (Author)
Double Resonance Production of Ionospheric Irregularities( Book )

1 edition published in 1972 in English and held by 1 WorldCat member library worldwide

A central question is the anomalously broad spectral width of the plasma line observed during ionospheric RF heating at Arecibo. The authors first suggested this is due to lower hybrid parametric instabilities but rejected it due to its high power threshold. They developed a numerical code which traces propagation and amplification of electron waves generated by ion acoustic parametric instability in a vertically stratified ionosphere. It is found that the plasma line observed by backscatter has a 'core' of locally generated and detected waves, and broad 'wings' of remotely generated high frequency waves. The wings are highly aspect and frequency sensitive. The authors also suggest that an intense RF pump should trap plasma waves in its field maxima, which may account for the fading observed in Boulder RF heating experiments. (Author)
High Altitude Plasma Effects( Book )

1 edition published in 1972 in English and held by 1 WorldCat member library worldwide

A major objective of this contract is to construct a Quiescent Uniform Ionospheric Plasma Simulator (QUIPS) to be used in analyzing and modeling the results of various field experiments in which a region of the ionosphere was artificially excited by a radar scattering. In this report the general design considerations for the facility are reviewed and a final design and fabrication schedule is presented. The current status of the construction as well as some of the preparations for the performance of the follow-on activities are described. (Author)
Electromagnetic scattering from aspherical non-uniform medium part i. general theory( Book )

1 edition published in 1962 in English and held by 1 WorldCat member library worldwide

The scattering of electromagnetic waves by a spherically symmetric continuous dielectric is examined. Two distinct methods for calculating the scattering amplitude are derived. It is shown that the scalar approximation is, in general, extremely poor. The radar cross section, is discussed in some detail. (Author)
High Altitude Plasma Effects. Parametric Excitation by an Electromagnetic Pump in a Large Laboratory Plasma (QUIPS: Quiescent Plasma Studies): First Results( Book )

1 edition published in 1973 in English and held by 1 WorldCat member library worldwide

A series of experiments are being carried out in the TRW large volume plasma facility, the QUIPS (Quiescent Plasma Studies) device. The purpose of the experiments is to study those parametric instabilities which are excited when high power microwaves propagate into a plasma cutoff region. The plasma instabilities have been observed with probes; in later experiments, Thompson radar scattering diagnostics will also be used. A variety of nonlinear effects which are consistent with the standard linear theory of parametric instabilities were observed, as well as other phenomena which are still the subject of theoretical study. The experimental results are grouped into the following topics: Parametric excitation of high frequency sidebands near the pump frequency; Excitation of low frequency oscillations; Propagation of ion acoustic waves in the presence of an electromagnetic wave pump; and Mode coupling of electron plasma waves and ion acoustic waves by an electromagnetic wave pump. (Author Modified Abstract)
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