Eur. Phys. J. D 42, 407-424 (2007)
https://doi.org/10.1140/epjd/e2007-00131-8

Microscopic quantities in discharge in air obtained from an electro-mechanical experiment

¹ CNR/INFM and Dipartimento di Matematica e Fisica, Università Cattolica del Sacro Cuore, via Musei 41, 25121 Brescia, Italy
² Centro de Fìsica Fundamental, Universidad de Los Andes, Mérida, 5101, Venezuela

Corresponding authors: ^a g.cavalleri@dmf.unicatt.it - ^b spavieri@ula.ve

Received: 19 September 2006
Revised: 20 January 2007
Published online: 23 March 2007

Abstract

The results of an experiment of impulsive electrodynamics [Eur. Phys. J. D 15, 87 (2001)] are shown to be due to electrons and ions in run-aways. By fitting the theoretical values with the experimental data, the values of microscopic quantities, at present unknown, can be derived, thus opening a new field of research. The obtained quantities are three, namely: (i) the contribution to air ionization due to the current (mainly of run-aways) and characterized by a parameter ρ; (ii) the product ζ=n_ein_ie (where n_ei is the number of ions extracted by one electron in run-away and n_ie the number of electrons extracted by one run-away ion colliding on the electrodes in electrical discharges with temperatures (for non run-aways) of ≃4×10⁴ K); (iii) the reconstruction time constant of the high-energy tail of the distribution function, from which we can derive the concentration per unit time of electrons and ions which become run-aways. The value is useful for the theoretical explanation of the electronic noise with power spectral density inversely proportional to the frequency.