Hostname: page-component-77c89778f8-5wvtr Total loading time: 0 Render date: 2024-07-16T13:59:27.848Z Has data issue: false hasContentIssue false
  • English
  • Français

Coherent Radiation from Electrostatic Double Layers

Published online by Cambridge University Press:  19 July 2016

Jan Kuijpers
Jan Kuijpers*
Affiliation:
Sterrekundig Instituut Utrecht P.O. Box 80 000 3508 TA Utrecht The Netherlands

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The radiation properties of electrostatic double layers (DLs) are of potential significance for cosmic magnetic explosions. If the emission is sufficiently intense it can serve as a diagnostic tool for particle acceleration by localized strong potential drops in current-carrying plasmas. Moreover such intense emission may form the explanation of some of the observed intense and narrow-band bursts of radiation from stellar and planetary magnetospheres. Here we study the efficiency of two coherent radiation processes: antenna radiation and a maser process. It is found that both processes can operate in the DL to produce intense and narrow-band emission. Antenna radiation occurs if the dimensions of the double layer are smaller than the wavelength of the emitted radiation. This process is therefore relevant to laboratory rather than to astrophysical plasmas. The maser on the other hand requires an amplification length inside the double layer much larger than the emitted wavelength, and can lead to observable emission in astrophysical circumstances. The growth is exponential and the rate depends only on the electric field energy density of the DL. Since the latter is externally controlled by the electric circuit it is a constant for the emission process so as to constitute a true maser. The maximum brightness temperature is of order 1025K. Masing radiation from electrostatic DLs is therefore a candidate for some of the observed intense narrow-band cosmic radio emission.

Type
VIII. Solar Flares
Information
Symposium - International Astronomical Union , Volume 142: Basic Plasma Processes on the Sun , 1990 , pp. 365 - 373
Copyright
Copyright © Kluwer 1990 

References

Alfvén, H.: 1958, Tellus 10, 104.CrossRefGoogle Scholar
Alfvén, H.: 1981, Cosmic Plasma, D. Reidel Publ. Cy., Dordrecht, Netherlands.Google Scholar
Allaart, M.A.F. and van Nieuwkoop, J.: 1989, Solar Phys. submitted.Google Scholar
Aly, J.J. and Kuijpers, : 1989, Astron. Astrophys., in press.Google Scholar
Bostrom, R., Holback, B., Holmgren, G., Koskinen, H.: 1988 Physica Scripta 39, 782.Google Scholar
Hultqvist, B.: 1989, Phil. Trans. Royal Soc. London A 328, 209.Google Scholar
Jacobsen, C. and Carlqvist, P.: 1964, Icarus 3, 270.Google Scholar
Krishan, V. and Sivaram, C.: 1983, Solar Phys. 84, 125.CrossRefGoogle Scholar
Kuijpers, J.: 1989a, Solar Phys. 121, 163.Google Scholar
Kuijpers, J.: 1989b, in Plasma Phenomema in the Solar Atmosphere, eds. Dubois, M.A. and Grésillon, D., Cargèse, France.Google Scholar
Leblanc, Y.: 1989, in Plasma Phenomema in the Solar Atmosphere, eds. Dubois, M.A. and Grésillon, D., Cargèse, France, in press.Google Scholar
Lindberg, L.: 1988, Astrophys. Space Sci. 144, 3.CrossRefGoogle Scholar
Melrose, D.B.: 1980, Plasma Astrophysics II, Gordon and Breach Publ., New York, p. 349.Google Scholar
Melrose, D.B.: 1986, Instabilities in Space and Laboratory Plasmas, Cambridge Univ. Press, Cambridge, U.K., Ch. 6.Google Scholar
Raadu, M.A.: 1984, Proc. 2nd Symp. on Plasma Double Layers, eds. Schrittwieser, R. and Eder, G., Innsbruck, p. 3.Google Scholar
Raadu, M.A.: 1989, Physics Reports, 178, 25.Google Scholar
Raadu, M.A. and Rasmussen, J.J.: 1988, Astrophys. Space Sci. 144, 43.Google Scholar