The report suggests possible ways for further theoretical study of the interaction of an electron beam and the ions in a hot-electron plasma. Equations are obtained for beamplasma interaction in a filled cylindrical waveguide in which the thermal velocity distribution is longitudinal but otherwise arbitrary. An approximation is described based on these equations by using only one transverse wave number. A close resemblance is found between the approximate solutions and the theory of plane waves in an infinite beamplasma system, traveling at an angle with the direction of the beam and the magnetic field and having a certain fixed real transverse wave number. Advantage is taken of this resemblance to calculate beam- (hot-electron) plasma interaction including a transverse random velocity distribution. The theory of a filamentary beam is combined with that of a plasma-filled waveguide, using the coupling-of-modes theory, for the description of some of the weak interactions between a thin beam and a finite plasma. (Author).

Physics of Intense Beams in Plasmas is a comprehensive description of the interaction between extremely intense particle beams and plasmas. The emphasis is on experimental beam-plasma physics, but the necessary theory is also explained-much of which is innovative and original. Central to the book is the discussion of beam instabilities, emphasizing their hydrodynamic nature.

Cyclotron Waves in Plasma is a four-chapter text that covers the basic physical concepts of the theory of cyclotron waves and cyclotron instabilities, brought about by the existence of steady or alternating plasma currents flowing perpendicular to the magnetic field. This book considers first a wide range of questions associated with the linear theory of cyclotron oscillations in equilibrium plasmas and in electron plasmas in metals and semiconductors. The next chapter deals with the parametric excitation of electron cyclotron oscillations in plasma in an alternating electric field. A chapter focuses on plasma turbulence, which results from the development of cyclotron instabilities. The last chapter discusses pertinent experimental data concerning cyclotron waves in plasma. The book is intended for specialists in plasma physics and a number of related fields, including the physics of the ionosphere, solar wind and, metals, as well as for students and teachers who are specializing in these subjects.

AD-2 1 3749N2 AD-261 375Div. 1U (16 Aug 61) OTS price $1.00 National Aeronautics and Space Administr tion, Washington, D.C. SOUND PRESSURES AND CORRELATION OF NOISE ON THE FUSELAGE OF A JET AIRCRAFT IN FLIGHT, by Russell D. Shattuck. Aug 61, 32p. incl. illus. tables (NASA technical note no. D-1086) Unclassified reportAlso available from NASA, Wash. 25, D.C., as NASA Technical note D-1086. DESCRIPTORS: *Jet plane oi, Fus lages, Pressure, Flight testing, Boundary layer, *Jet engine noise, Flight, Velocity, Jet bombers, Acoustics, Microphones, Sound, Jet planes, Measurement. Open-ended Terms: B-57. T s r co uc l itu es of 10,000, 20,000, and 30,000 feet at speeds of Mach 0.4, 0.6, and 0.8. It was found that the sound pressure levels on the aft fuselage of a jet aircraft in flight can be estimated using an equation involving the tru airsp d an th fr e air d n ity. The cross-correlation coefficient over a spacing of 2.5 feet was generalized with Strouhal number. The spectrum of the noise in flight is comparatively flat up to 10,000 cycles per second. (Author).

International Series of Monographs in Natural Philosophy: Collective Oscillations in a Plasma, Volume 7 presents specific topics within the general field of radio waves propagation. This book contains five chapters that address the theory of linear oscillations in a plasma, the spectra of the eigen oscillations, and the mechanism of high-frequency heating. The opening chapters deal with the self-consistent fields; development of initial perturbation; dispersion permittivity tensor of a plasma in a magnetic field; effect of thermal motion of particles on low-frequency resonances; excitation of oscillations by modulated azimuthal currents; and cyclotron damping of low-frequency oscillations. The next chapters describe the nature of beam instability, the fluctuations in a free equilibrium plasma, and the current causing scattered waves. A study of the probability of scattering is presented. The concluding chapters are devoted to the scattering of electromagnetic waves in a plasma-beam system and the coefficient of reflection determination. The book can provide useful information to scientists, physicists, students, and researchers.