Intense microwave pulse propagation through gas breakdown plasmas in a waveguide

Technical Report · Wed Oct 08 04:00:00 EDT 1986

DOI:https://doi.org/10.2172/7242247· OSTI ID:7242247

Byrne, D P

High-power microwave pulse-compression techniques are used to generate 2.856 GHz pulses which are propagated in a TE/sub 10/ mode through a gas filled section of waveguide, where the pulses interact with self-generated gas-breakdown plasmas. Pulse envelopes transmitted through the plasmas, with duration varying from 2 ns to greater than 1 ..mu..s, and peak powers of a few kW to nearly 100 MW, are measured as a function of incident pulse and gas pressure for air, nitrogen, and helium. In addition, the spatial and temporal development of the optical radiation emitted by the breakdown plasmas are measured. For transmitted pulse durations greater than or equal to 100 ns, good agreement is found with both theory and existing measurements. For transmitted pulse duration as short as 2 ns (less than 10 rf cycles), a two-dimensional model is used in which the electrons in the plasma are treated as a fluid whose interactions with the microwave pulse are governed by a self-consistent set of fluid equations and Maxwell's equations for the electromagnetic field. The predictions of this model for air are compared with the experimental results over a pressure range of 0.8 torr to 300 torr. Good agreement is obtained above about 1 torr pressure, demonstrating that microwave pulse propagation above the breakdown threshold can be accurately modeled on this time scale. 63 refs., 44 figs., 2 tabs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 7242247
• Report Number(s): UCRL-53764; ON: DE87002752
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700103* -- Fusion Energy-- Plasma Research-- Kinetics
BREAKDOWN
DATA
DATA ACQUISITION SYSTEMS
ELECTROMAGNETIC RADIATION
ELECTRON DENSITY
EXPERIMENTAL DATA
INFORMATION
MICROWAVE RADIATION
NUMERICAL DATA
PLASMA
RADIATIONS
TIME DEPENDENCE
WAVE PROPAGATION
WAVEGUIDES