Journal cover Journal topic
Annales Geophysicae An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 1.490
IF 5-year value: 1.445
IF 5-year
CiteScore value: 2.9
SNIP value: 0.789
IPP value: 1.48
SJR value: 0.74
Scimago H <br class='widget-line-break'>index value: 88
Scimago H
h5-index value: 21
Volume 23, issue 1
Ann. Geophys., 23, 101–107, 2005
© Author(s) 2005. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: Eleventh International EISCAT Workshop

Ann. Geophys., 23, 101–107, 2005
© Author(s) 2005. This work is distributed under
the Creative Commons Attribution 3.0 License.

  31 Jan 2005

31 Jan 2005

Pulsed energy storage antennas for ionospheric modification

R. F. Wuerker1,*, J. Chen1, W. Beam2, and E. Nichols2 R. F. Wuerker et al.
  • 1UCLA Plasma Physics Lab., Los Angeles, CA 90095, USA
  • 2HIPAS Observatory Two Rivers, AK 99712, USA
  • *now retired from UCLA

Abstract. 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.

Publications Copernicus