Advertisement

Step-Wise Propagation of Long Streamer in Electronegative Gases

  • Nickolay L. Aleksandrov
  • Edward M. Bazelyan

Abstract

Observations and numerical simulation showed a step-wise development of a long streamer in highly non-uniform gaps at rising applied voltage.1,2This was obtained in electronegative gases such as air, 02 and SF6. It is known that the plasma in the streamer channel is characterized by a high density of charged particles (electron density n e ~ 1013 −1015 cm−3) and a considerable difference between electron temperature and gas temperature. Electron-ion recombination and electron attachment to a molecule in the streamer channel of radius r reduce fast the value of n e and consequently the conductivity γ = πr 2 en e μ e per unit channel length where µ e is the electron mobility. The plasma decay does not need to lead to a decrease of the streamer current which is written as
$$ {i_s} \approx {C_s}{\varphi _t}{v_s} + {C_s}{L_s}\frac{{dU}}{{dt}} $$
(1)
The first term on the right-hand side is determined by delivery of charge to the new streamer sections that must be charged up to the potential φ 1 of the streamer tip. This component of the current decreases with decreasing channel conductivity.The second term in Eq. (1) describes recharging the formed channel of the length L s and of the capacitance C s per unit length when the applied voltage U 0(t) rises in time. Here, U is the time-varying average potential of the streamer. If the streamer develops at a sharp front of the voltage impulse (at high positive values of dU/dt), the total current i s can remain constant or even increase in spite of the plasma decay. This will result in a growth of the electric field in the decaying streamer channel:
$$ {E_s} = \frac{{{i_s}}}{{\pi {r^2}e{n_e}{\mu _e}}} $$
(2)

Keywords

Secondary Wave Applied Voltage Streamer Channel Electric Field Distribution Streamer Length 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    N. L. Aleksandrov and E. M. Bazelyan, Step Propagation of a Streamer in an Electronegative Gas, J. Exp. Theor. Phys. 91 724735 (2000).CrossRefGoogle Scholar
  2. 2.
    N. L. Aleksandrov and E. M. Bazelyan, The peculiarities of long-streamer propagation in gases with strong electron attachment, in : Proc. XIII Int. Conf. Gas Discharge and their Appl. (Glasgow) 1 430–433 (2000).Google Scholar
  3. 3.
    N. L. Aleksandrov and E. M. Bazelyan, Simulation of long-streamer propagation in air at atmospheric pressure, J. Phys. D: Appl. Phys. 29 740–752 (1996).CrossRefGoogle Scholar
  4. 4.
    R. Morrow, A survey of the electron and ion transport properties in SF6, IEEE Trans. Plasma ScL, PS-14 234–238(1986).CrossRefGoogle Scholar
  5. 5.
    E. M. Bazelyan and Yu. P. Raizer, Spark Discharge (CRC Press, Boca Raton, New York, 1998).Google Scholar
  6. 6.
    1. Gallimberti and N. Wiegart, Streamer and leader formation in SF6 and SF6 mixtures under positive impulse conditions: I Corona development, J. Phys. D: Appl. Phys. 19 23512362.Google Scholar
  7. 7.
    R. Morrow, Theory of Positive Corona in SF6 Due to a Voltage Impulse, IEEE Trans. Plasma Sci. 19 86–94 (1991).CrossRefGoogle Scholar
  8. 8.
    I. D. Chalmers, C. X. Wang and O. Farish, Restrikes in SF6 corona channels - a method of channel field assessment,J. Phys. D: Appl. Phys. 22 13211326.Google Scholar

Copyright information

© Springer Science+Business Media New York 2001

Authors and Affiliations

  • Nickolay L. Aleksandrov
    • 1
  • Edward M. Bazelyan
    • 2
  1. 1.Moscow Institute of Physics & TechnologyDolgoprudnyRussia
  2. 2.Krzhizhanovsky Power Engineering InstituteMoscowRussia

Personalised recommendations