Microscopic quantities in discharge in air obtained from an electro-mechanical experiment
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
Revised: 20 January 2007
Published online: 23 March 2007
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=neinie (where nei is the number of ions extracted by one electron in run-away and nie 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.
PACS: 05.60.Cd – Classical transport / 05.70.-a – Thermodynamics / 47.45.-n – Rarefied gas dynamics / 51.10.+y – Kinetic and transport theory of gases
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2007