Differential excitation cross sections of molecular oxygen by electron impact: The longest and second bands

Journal Article · Sun May 01 04:00:00 EDT 1994 · Physical Review A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.49.3680· OSTI ID:5008127

Shyn, T W; Sweeney, C J; Grafe, A ^[1]

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1. Space Physics Research Laboratory, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States)

We have measured absolute differential excitation cross sections for the longest and second bands of molecular oxygen by electron impact. A crossed-beam method was used. The angular range covered was 12[degree] to 156[degree], while the impact energy range was 15 to 50 eV. Two pronounced minima are present in the angular distributions of both cross sections, indicating in both cases substantial [ital D]-wave character. Additionally, the angular distributions show that both the longest and second bands are composite structures, arising from a combination of electric dipole allowed and electric dipole forbidden transitions. We also computed integrated cross sections from the present differential cross sections, and found a broad maximum in the former near 20-eV impact.

• OSTI ID: 5008127
• Journal Information: Physical Review A; (United States), Journal Name: Physical Review A; (United States) Vol. 49:5; ISSN PLRAAN; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

664300* -- Atomic & Molecular Physics-- Collision Phenomena-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR DISTRIBUTION
BEAMS
COLLIDING BEAMS
COLLISIONS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
DISTRIBUTION
ELECTRON COLLISIONS
ELECTRON-MOLECULE COLLISIONS
ELEMENTS
ENERGY-LEVEL TRANSITIONS
EXCITATION
INTEGRAL CROSS SECTIONS
MOLECULE COLLISIONS
NONMETALS
OXYGEN