Il Nuovo Cimento D

, Volume 15, Issue 10, pp 1301–1314 | Cite as

Fokker-Planck equation and relevant Chapman-Cowling-Davydov expression modified for coulomb scattering

  • G. Cavalleri
  • G. Mauri


TheP 1 approximation to the Boltzmann equation in the case of slightly ionized gases leads to the usual Fokker-Planck equation whose solution in steady-state condition is the Chapman-Cowling-Davydov (CCD) expression. We have extended the same procedure to include electron-ion interactions when the corresponding collision frequency is of the same order of, or larger than, the electron-neutral molecule collision frequency. We have considered a case where, after an initial ionization of a column of gas, the majority of the electrons have diffused to, and have been captured by, the walls of the chamber so that we may neglect the electron-electron interactions. We have found a modified CCD expression. However, numerical calculations show that the differences between the modified expressions and the standard ones in which the electron-ion collision frequency for momentum transfer is added to the electron-neutral collision frequency are beyond the present experimental accuracy.

PACS 52.25.Fi

Transport properties 

PACS 52.80.Dy

Low-field and Townsend discharges 

PACS 05.60

Transport processes: theory 


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Copyright information

© Società Italiana di Fisica 1993

Authors and Affiliations

  • G. Cavalleri
    • 1
  • G. Mauri
    • 2
  1. 1.Università Cattolica del Sacro CuoreBresciaItalia
  2. 2.Dipartimento di Matematica del Politecnico di MilanoMilanoItalia

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