Elastic scattering of fast electrons by H/sub 2/( /sup 1/. sigma. /sub g//sup +/) and N/sub 2/(X /sup 1/. sigma. /sub g//sup +/)

Journal Article · Sun Sep 01 04:00:00 EDT 1985 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.32.1384· OSTI ID:5350332

Liu, J W

The differential cross section (DCS) dsigma/sup el//d..cap omega.. for the elastic scattering of electrons by homonuclear diatomic molecules in the first Born approximation at scattering angles equal or near zero is derived here by an expansion method. This method gives dsigma/sup el//d..cap omega.. = ..cap alpha..+..beta..K/sup 2/+..gamma..K/sup 4/+.. ., where ..cap alpha..,..beta..,..gamma.. are constants, and K is the momentum transfer. For H/sub 2/, the value ..cap alpha.. with vibrational corrections is calculated with use of the most accurate wave function given by Kolos and Wolniewicz (KW) and the values for the constants ..beta.. and ..gamma.. are evaluated from the Davidson and Jones (DJ) wave function. The resulting DCS's at small scattering angles are given for comparison with experiment. The disagreement between theory and experiment for H/sub 2/ is found when the scattering angle is less than 15 mrad at 25 keV (i.e., K = 0.6 a.u.). The disagreement is very similar to the ones reported in the studies of Compton scattering and (e,2e) reaction spectroscopy. The disagreement between theory and experiment at scattering angles near zero for N/sub 2/ are also reported. New experimental data for H/sub 2/ and N/sub 2/ at very small scattering angles may be needed in order to establish the disagreements reported here. The DCS for N/sub 2/ at large scattering angles is also calculated using an accurate multiconfiguration self-consistent-field first-order configuration-interaction (MCSCF-FOCI) wave function. Good agreement within experimental resolution at large scattering angles is found for N/sub 2/ for the difference function ..delta..N(K) and for the DCS. This is contrary to the recent study of H/sub 2/ where discrepancies were reported at large scattering angles.

• Research Organization: Division of Physics, National Research Council of Canada, Montreal Road, Ottawa, Canada K1A0R6
• OSTI ID: 5350332
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 32:3; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
BORN APPROXIMATION
COLLISIONS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
ELASTIC SCATTERING
ELECTRON COLLISIONS
ELECTRON-MOLECULE COLLISIONS
ELEMENTS
HYDROGEN
MOLECULE COLLISIONS
NITROGEN
NONMETALS
SCATTERING
SMALL ANGLE SCATTERING