Accession Number : ADA250710

Title :   Electromagnetic-Wave Propagation in Unmagnetized Plasmas

Descriptive Note : Final rept. 1 May 1989-31 Jan 1992

Corporate Author : HUGHES RESEARCH LABS MALIBU CA

Personal Author(s) : Gregoire, D. J. ; Santoru, J. ; Schumacher, R. W.

PDF Url : ADA250710

Report Date : MAR 1992

Pagination or Media Count : 65

Abstract : This final report describes an investigation of electromagnetic-wave propagation in unmagnetized plasmas and its application to the reduction of the radar cross section (RCS) of a plasma-filled enclosure. We have demonstrated RCS reduction of 20 to 25 dB with a prototype system at the radar range at Hughes Aircraft's Microwave Products Division in Torrance. The prototype consists of a sealed ceramic enclosure with a microwave reflector and a plasma generator inside it. When the plasma is present, the RCS is significantly reduced over a frequency range of 4 to 14 GHz. As part of the program, we also investigated the basic-plasma-physics issues relating to the absorption and refraction of electromagnetic (EM) waves in collisional plasmas. We demonstrated absorption as high as 63 dB in a section of plasma-loaded C-band rectangular waveguide. We also developed a theoretical model for the plasma cloaking process that includes scattering contributions from the plasma-vacuum interface, partial reflections from the plasma, and collisional absorption in the plasma. The theoretical model is found to be in reasonable agreement with the experimental results and can be used to confidently design future plasma cloaking systems. Plasma Cloaking, RCS Reduction.

Descriptors :   *PLASMAS(PHYSICS), *ELECTROMAGNETIC WAVE PROPAGATION, *RADAR COUNTERMEASURES, *STEALTH TECHNOLOGY, SCATTERING, MODELS, INTERFACES, VACUUM, PROTOTYPES, WAVEGUIDES, MICROWAVES, RADAR, REFLECTION, REDUCTION, WAVE PROPAGATION, ABSORPTION, REFRACTION, PLASMA GENERATORS, REFLECTORS, C BAND, RADAR ABSORBING MATERIALS.

Subject Categories : Electrical and Electronic Equipment
      Radar Countermeasures
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE