Accession Number : AD0693024

Title :   VACUUM TUBE RESEARCH PROJECT.

Descriptive Note : Quarterly status rept. no. 16, 1 Jan-31 Mar 57,

Corporate Author : CALIFORNIA INST OF TECH PASADENA ELECTRON TUBE AND MICROWAVE LAB

Personal Author(s) : Field,Lester M. ; Gould,Roy W.

Report Date : 31 MAR 1957

Pagination or Media Count : 21

Abstract : The first plasma amplifier was successfully operated and interaction between the plasma electrons and the electron beam was detected. A 5 db variation in gain with arc current results and the arc current required for maximum gain varies approximately as the square of the operating frequency. Reflection of electromagnetic waves from a cylindrical column of plasma placed in a rectangular waveguide indicates two maxima in the reflection coefficient instead of a single maxima as predicted by the elementary theory. This effect has sometimes been noticed by other workers but it has no accepted explanation. The change in the resonant frequency of the plasma column due to a radial variation in electron density has been computed and it is found that if the density varies by less than a factor of 2 the resonant frequency is determined by the average electron density. The normalized surface admittance just above a thin strip beam in Brillouin flow was found for two cases. Several of the design relations for thin beam M-type backward-wave oscillators were obtained. Propagation of space charge waves in an accelerated electron beam of finite diameter is being investigated. (Author)

Descriptors :   (*ELECTRON TUBES, SCIENTIFIC RESEARCH), AMPLIFIERS, PLASMAS(PHYSICS), ELECTROMAGNETIC RADIATION, SCATTERING, ELECTRON DENSITY, BACKWARD WAVE OSCILLATORS, MICROWAVE EQUIPMENT, SPACE CHARGE, ELECTRON BEAMS, RESONANT FREQUENCY

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE