Statistical effects in high-power microwave beam propagation
At very high power levels pulsed microwave beams can generate air-breakdown plasmas which may limit the fluence that the beam can transport through the atmosphere. Conventional air breakdown is an avalanche process wherein free electrons, driven by the microwave fields, produce ionization through collisions with air molecules. Propagation of a beam is affected when the plasma electron density approaches the critical density for the particular microwave frequency. The rate of growth of the plasma depends on the competition between the ionization probability and electron loss processes such as attachment and diffusion. The physics of the avalanche process is reasonably well understood, and fluence limits can be fairly accurately predicted, so long as there are free seed electrons to initiate the breakdown. At sea level and low altitudes, seed electrons are, in fact, expected to be fairly rare, and air breakdown, and the consequences for beam propagation, must be treated as a statistical problem; the effective fluence limit may be much greater than would be predicted on the basis of conventional breakdown thresholds. The statistical effects are currently being investigated. 13 refs., 2 figs.
- Research Organization:
- Lawrence Livermore National Lab., CA (USA)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 7167952
- Report Number(s):
- UCRL-97832; CONF-8805132-11; ON: DE88012440
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
AIR
BEAM PULSERS
BREAKDOWN
DATA
ELECTRIC DISCHARGES
ELECTROMAGNETIC RADIATION
EXPERIMENTAL DATA
FLUIDS
GASES
HIGH-FREQUENCY DISCHARGES
INFORMATION
IONIZATION
MATHEMATICS
MICROWAVE POWER TRANSMISSION
MICROWAVE RADIATION
NUMERICAL DATA
PLASMA PRODUCTION
POWER TRANSMISSION
RADIATION EFFECTS
RADIATIONS
STATISTICS
WAVE PROPAGATION