Europhys. Lett.
Volume 74, Number 3, May 2006
Page(s) 431 - 437
Section Physics of gases, plasmas and electric discharges
Published online 22 March 2006
Europhys. Lett., 74 (3), pp. 431-437 (2006)
DOI: 10.1209/epl/i2005-10542-y

Why does a low-pressure wire-discharge exist self-sustained?

M. Makarov1, Y. Loumani1, T. Minea2, G. Gousset2 and A. Kozyrev3

1  SOPRA SA - 26 rue Pierre Joigneaux, 92270 Bois-Colombes, France
2  LPGP, Université Paris XI - 91405 Orsay, France
3  IHCE - 4 ave. Akademicheski, 650055, Tomsk, Russia

received 30 December 2005; accepted in final form 28 February 2006
published online 22 March 2006

Numerical study of a self-sustained low-pressure (6.8$\un{Pa}$ or 50 $\un{mTorr}$) wire discharge in helium is reported. The current-independent voltage drop across the cathode sheath is found to be of ~250$\un{V}$. The other part of the discharge voltage is essentially applied across the anode sheath. It drains electrons from the quasi-neutral plasma and thus presents a necessary condition for discharge maintenance. Two major groups of electrons have been distinguished: the fast electrons of ~(24-250)$\un{eV}$, as well as a very small fraction of hot (run-away) electrons with the energy close to the discharge voltage, are responsible for gas ionization throughout negative glow while the thermalized electrons of ~1's eV are easily captured by the anode and so removed from the discharge.

52.80.Hc - Glow; corona.
52.65.Pp - Monte Carlo methods.
52.65.Rr - Particle-in-cell method.

© EDP Sciences 2006