Accession Number : AD0274635

Title :   ROTATIONAL EXCITATION AND MOMENTUM TRANSFER CROSS SECTIONS FOR ELECTRONS IN H2 AND N2 FROM TRANSPORT COEFFICIENTS

Corporate Author : WESTINGHOUSE ELECTRIC CORP PITTSBURGH PA

Personal Author(s) : FROST, L.S. ; PHELPS, A.V.

Report Date : 19 FEB 1962

Pagination or Media Count : 1

Abstract : The theoretical values of the transport coefficients were obtained by calculating accurate electron energy distribution functions using an assumed set of elastic and inelastic cross sections. The discrete nature of the energy loss occurring in a rotational or vibrational excitation collision was included in the theory, as were collisions of the second kind with thermally excited molecules. The resulting values of drift velocity and characteristic energy, D/mu, were compared with experimental data, and adjustments were made in the assumed cross sections until good agreement was obtained. The final values of the rotational excitation cross sections are 2.5 times the values computed using the latest available values for the molecular electric quadrupole moments. In hydrogen, the analysis has been extended to energies for which vibrational excitation is important. A vibrational cross section with a maximum of roughly 5 x 10 to the -17th power sq. cm at 3 ev is consistent with the measurements. (Author)

Descriptors :   *ELECTRONS, *HYDROGEN, *NITROGEN, *QUANTUM THEORY, DIFFUSION, ELASTIC SCATTERING, ENERGY, EXCITATION, INELASTIC SCATTERING, MOLECULES, QUADRUPOLE MOMENT, ROTATION, STATISTICAL DISTRIBUTIONS, STATISTICAL FUNCTIONS, THEORY, TRANSPORT PROPERTIES, VELOCITY.

Distribution Statement : APPROVED FOR PUBLIC RELEASE