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Titel |
Pulsed energy storage antennas for ionospheric modification |
VerfasserIn |
R. F. Wuerker, J. Chen, W. Beam, E. Nichols |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 23, no. 1 ; Nr. 23, no. 1 (2005-01-31), S.101-107 |
Datensatznummer |
250015124
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Publikation (Nr.) |
copernicus.org/angeo-23-101-2005.pdf |
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Zusammenfassung |
Interesting, "new", very high peak-power pulsed radio frequency (RF)
antennas have been assembled at the HIPAS Observatory (Alaska, USA) and also
at the University of California at Los Angeles (UCLA, USA); namely, a pair
of quarter wavelength (λ/4) long cylindrical conductors separated
by a high voltage spark gap. Such a combination can radiate multi-megawatt
RF pulses whenever the spark gap fires. The antenna at HIPAS is 53m
long (λ/2) with a central pressurized SF6 spark gap. It is
mounted 5 meters (λ/21) above a ground plane. It radiates at 2.85MHz.
The two antenna halves are charged to ± high voltages by a Tesla
coil. Spark gap voltages of 0.4 MV (at the instant of spark gap closure)
give peak RF currents of ~1200A which correspond to ~14 MW peak
total radiated power, or ~56 MW of Effective Radiated Power (ERP). The
RF pulse train is initially square, decaying exponentially in time with Qs
of ~50. Two similar but smaller 80-MHz antennas were assembled at UCLA
to demonstrate their synchronization with a pulsed laser which fired the
spark gaps in the two antennas simultanoeously. These experiments show that
one can anticipate a pulsed array of laser synchronized antennas having a
coherent Effective Radiated Power (ERP)>10GW. One can even reconsider a
pulse array radiating at 1.43MHz which corresponds to the electron gyrofrequency
in the Earth's magnetic field at ~200km altitude. These
"new" pulsed high power antennas are hauntingly similar to the ones used
originally by Hertz (1857-1894) during his (1886-1889) seminal
verifications of Maxwell's (1864) theory of electrodynamics. |
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